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Ideal for residents, fellows, and practicing radiologists, Genitourinary Imaging is designed to provide a range of common to less commonly seen cases for sharpening diagnostic skills in this challenging subspecialty area. As part of the bestselling Case Review Series, this title allows you to test and build your knowledge with access to a wide range of cases in genitourinary radiology, making it an ideal resource for both certification and maintenance of certification (MOC) exams.

  • Mimics the format of official exams and the daily clinical environment with a pedagogically anchored layout that introduces cases/images as unknowns with three to four questions, followed by diagnosis, answers, additional commentary, references and cross-references to the corresponding Requisites volume are supplied in logical succession.
  • Blank space available for note taking.
  • An ideal study companion when paired with the corresponding Requisites series title, Genitourinary Radiology.
  • Covers the latest hot topics in genitourinary radiology, including prostate MR imaging and staging gynecologic malignancies with functional MRI.
  • In-depth reviews of diseases involving renal collecting systems and ureters that are diagnosed by CT urography (such as papillary necrosis, medullary sponge kidney, and urothelial neoplasms).
  • Increased number of interactive case presentations featuring updated figures, recent imaging techniques, and additional supporting images for further review.
  • Medicine eBook is accessible on a variety of devices.

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Genitourinary Imaging
Case Review
THIRD EDITION
Satomi Kawamoto, MD
Associate Professor of Radiology, The Russell H. Morgan Department of Radiology and
Radiological Science, The Johns Hopkins University School of Medicine, Baltimore,
Maryland
Katarzyna J. Macura, MD, PhD, FACR, FSCBTMR
Associate Professor of Radiology, Urology, and Oncology, The Russell H. Morgan
Department of Radiology and Radiological Science, The James Buchanan Brady Urological
Institute, The Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University
School of Medicine, Baltimore, Maryland
Case Review SeriesTable of Contents
Cover image
Title page
Series page
Copyright
Dedication
Series Foreword
Book Foreword
Preface
Acknowledgment
Opening Round
Fair Game
Challenge
Supplemental Figures
Index of Cases
Index of TermsSeries Page
SERIES EDITOR
David M. Yousem, MD, MBA
Professor of Radiology
Director of Neuroradiology
Russell H. Morgan Department of Radiology and Radiological Science
The Johns Hopkins Medical Institutions
Baltimore, Maryland
Other Volumes in the CASE REVIEW Series
Brain Imaging, Second Edition
Breast Imaging, Second Edition
Cardiac Imaging, Second Edition
Duke Review of MRI Principles
Emergency Radiology
Gastrointestinal Imaging, Third Edition
General and Vascular Ultrasound, Second Edition
Head and Neck Imaging, Fourth Edition
Musculoskeletal Imaging, Second Edition
Nuclear Medicine, Second Edition
Obstetric and Gynecologic Ultrasound, Third Edition
Pediatric Imaging, Second Edition
Spine Imaging, Third Edition
Thoracic Imaging, Second Edition
Vascular and Interventional Imaging, Second EditionCopyright
1600 John F. Kennedy Blvd.
Ste 1800
Philadelphia, PA 19103–2899
GENITOURINARY IMAGING: CASE REVIEW SERIES, THIRD EDITION
ISBN: 978-0-323-08569-4
Copyright © 2016 by Elsevier Inc. All rights reserved.
All rights reserved. No part of this publication may be reproduced or transmitted in
any form or by any means, electronic or mechanical, including photocopying,
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about the Publisher’s permissions policies and our arrangements with organizations
such as the Copyright Clearance Center and the Copyright Licensing Agency, can be
found at our website: www.elsevier.com/permissions.
This book and the individual contributions contained in it are protected under
copyright by the Publisher (other than as may be noted herein).
Notices
Knowledge and best practice in this field are constantly changing. As new research
and experience broaden our understanding, changes in research methods,
professional practices, or medical treatment may become necessary.
Practitioners and researchers must always rely on their own experience and
knowledge in evaluating and using any information, methods, compounds, or
experiments described herein. In using such information or methods they should
be mindful of their own safety and the safety of others, including parties for whom
they have a professional responsibility.
With respect to any drug or pharmaceutical products identified, readers are advised
to check the most current information provided (i) on procedures featured or (ii) by
the manufacturer of each product to be administered, to verify the recommended
dose or formula, the method and duration of administration, and contraindications.
It is the responsibility of practitioners, relying on their own experience and
knowledge of their patients, to make diagnoses, to determine dosages and the best
treatment for each individual patient, and to take all appropriate safety
precautions.To the fullest extent of the law, neither the Publisher nor the authors, contributors,
or editors, assume any liability for any injury and/or damage to persons or property
as a matter of products liability, negligence or otherwise, or from any use or
operation of any methods, products, instructions, or ideas contained in the material
herein.
Copyright © 2007, 2000 by Mosby, Inc., an affiliate of Elsevier Inc.
Library of Congress Cataloging-in-Publication Data
Kawamoto, Satomi, author.
Genitourinary imaging : case review / Satomi Kawamoto, Katarzyna J. Macura. —
Third edition.
p. ; cm. — (Case review series)
Preceded by Genitourinary imaging : case review / Ronald J. Zagoria, William W.
Mayo-Smith, Julia R. Fielding. 2nd ed. c2007.
Includes bibliographical references and indexes.
ISBN 978-0-323-08569-4 (pbk. : alk. paper)
I. Macura, Katarzyna J., author. II. Zagoria, Ronald J. Genitourinary imaging.
Preceded by (work): III. Title. IV. Series: Case review series.
[DNLM: 1. Female Urogenital Diseases—diagnosis—Examination Questions. 2.
Diagnostic Imaging—Examination Questions. 3. Male Urogenital Diseases—diagnosis
—Examination Questions. WJ 18.2]
RC874
616.6′075—dc23
2015008349
Content Strategist: Helene Caprari
Content Development Specialist: Katy Meert
Publishing Services Manager: Patricia Tannian
Senior Project Manager: Claire Kramer
Design Direction: Ashley MinerD e d i c a t i o n
To my husband, Hisataka, and our child, Keita.
Thank you for your love, patience, and support.
— S K
To Mom and Dad, who taught me persistence without which I would not be able to succeed.
To Tomek and Wiktor, who brought me joy and gave me reasons to brag.
To Robert, whose love, patience, and understanding made this and many other projects
possible.
— K J MSeries Foreword
I have been very gratified by the popularity and positive feedback that the authors of
the Case Review S eries have received on the publication of the editions of their
volumes. Reviews in journals and online sites as well as word-of-mouth comments
have been uniformly favorable. The authors have done an outstanding job in filling
the niche of an affordable, easy-to-access, case-based learning tool that supplements
the material in The Requisites series. I have been told by residents, fellows, and
practicing radiologists that the Case Review S eries books are the ideal means for
studying for oral board examinations and subspecialty certification tests.
A lthough some students learn best in a noninteractive study book mode, others
need the anxiety or excitement of being quizzed. The selected format for the Case
Review S eries (which consists of showing a few images needed to construct a
differential diagnosis and then asking a few clinical and imaging questions) was
designed to simulate the board examination experience. The only difference is that
the Case Review books provide the correct answer and immediate feedback. The limit
and range of the reader’s knowledge are tested through scaled cases ranging from
relatively easy to very hard. The Case Review S eries also offers feedback on the
answers, a brief discussion of each case, a link back to the pertinent The Requisites
volume, and up-to-date references from the literature. I n addition, we have recently
included labeled figures, figure legends, and supplemental figures in a new section at
the end of the book, which provide the reader more information about the case and
diagnosis.
Because of the popularity of online learning, we have been rolling out new editions
on the Web. We also have adjusted to the new Boards format, which will be electronic
and largely case based. We are ready for the new boards! The Case Reviews are now
hosted online at https://expertconsult.inkling.com. The interactive test-taking format
allows users to get real-time feedback, “pinch-and-zoom” figures for easier viewing,
and links to supplemental figures and online references. Personally, I am very excited
about the future. Join us.
David M. Yousem, MD, MBABook Foreword
Genitourinary Imaging: Case Review , third edition, by D rs. Kawamoto and Macura
breathes new life into this volume of the Case Review S eries (CRS ). Here at my home
base at J ohns Hopkins, S atomi and Katarzyna (Kasia) are known as two of the “best
and the brightest” on our faculty. They combine special gifts of great clinical acumen
with innovative research ideas. Their teaching skills are exemplary as graded each
year by the residents, so it was with that knowledge in hand that I encouraged them
to take up the Genitourinary volume after so many great cases supplied in the first two
editions by D rs. Zagoria, Mayo-S mith, and Fielding. D rs. Kawamoto and Macura
relied in part on S ociety of Uroradiology Guidelines for Resident Curriculum and
Training to ensure that they covered the full gamut of potential cases and that they
also brought the volume to state of the art imaging by including more examples of
computed tomography urography, pelvic magnetic resonance imaging, and even
functional imaging as part of their collection. Kasia is known as one of the electronic
media gurus in the department and developed computer-assisted educational
programs early in her radiology career. For her the challenge of teaching this material
using, in part, a Web-based approach was most fun. S he is skilled in using interactive
features to engage the learner and translate that to improved retention of key
diagnostic concepts.
A s always this volume of the CRS emphasizes differential diagnoses, multiple
choice questions, a summary of the current thinking on the entity, up-to-date
references, and cross-referencing to The Requisites volume. I expect that this
wonderful contribution by these outstanding authors will become the “go to” book
for mastering genitourinary imaging and will be the “study of choice” for residents
preparing for the new boards format.
I welcome my colleagues and friends S atomi Kawamoto and Kasia Macura to the
CRS family and thank them for their stellar work in producing this latest volume.
David M. Yousem, MD, MBA, Case Review Series EditorPreface
When I had an invitation from D r. D avid Yousem to serve as a coeditor of the third
edition of Genitourinary Imaging: Case Review Serie,s I was very excited about this
project.
The aim of writing this book is to provide a wide range of case-based learning
materials in genitourinary imaging for residents, fellows, and practicing radiologists
both in a conventional book format and as a Web-based learning module.
I elaborated on the previous edition to include the following three things:
1. Covering a wide range of entities in genitourinary radiology. Most cases categorized
in “Opening Round” and “Fair Game” and some of the cases categorized in
“Challenge” were selected from the Society of Uroradiology (SUR) Guidelines for
Resident Curriculum and Training in Genitourinary Radiology. Most of these cases
are encountered frequently in a busy clinical practice. Some rare challenging cases
that are not included in SUR Guidelines but contain important teaching points or
imaging finding to establish the diagnosis are also included.
2. Adding questions and comments that are useful for understanding the entity and
helpful for preparing for the examination given by the American Board of
Radiology and for clinical practice.
3. Showing up-to-date figures, including computed tomography urography, because
imaging techniques keep improving and making significant impacts on the
diagnosis and treatment of genitourinary disease.
I hope this edition of Genitourinary Radiology of the Case Review S eries is of help
for radiology residents, fellows, or radiologists who are interested in learning
genitourinary radiology.
Satomi Kawamoto, MD
When D avid Yousem, the series editor for the Case Review S eries and our colleague
from J ohns Hopkins, invited S atomi and me to contribute to the third edition of
Genitourinary Imaging: Case Review Serie sand mentioned that in the new format the
case review would be presented as both a hard copy and an electronic book, I eagerly
accepted the offer and was excited about the opportunity to create interactive case
vigne9 es for this review. My first encounter with teaching radiology with the
casebased approach dates back to my pre-residency times in the early 1990s. While at the
Medical College of Georgia, I worked with D r. Eugene F. Binet, Chairman of the
1Radiology D epartment at the time, on his electronic textbook for radiology known as
3 2R . I designed a digital case library to be an educational resource for radiologists
and envisioned that a searchable repository of radiologic cases would become a useful
tool for educational applications of the future. Fast forward two decades and I
welcomed the opportunity to share my own expertise and cases with radiologists in
training and beyond who wish to review a spectrum of imaging findings for
genitourinary diseases.I n this new edition, we are presenting cases with a multimodality approach to
illustrate the spectrum of imaging findings for entities ranging from congenital
anomalies, through a variety of benign conditions, to an array of malignancies. We
include some of the newest functional imaging techniques, for example, diffusion and
perfusion imaging for magnetic resonance imaging cases or positron emission
tomography for oncologic imaging.
We are indebted to authors of prior editions of the book because they produced a
wonderful resource for review of imaging of genitourinary disease by presenting
cases that maintain their outstanding educational value. With this third edition, we
extend the collection to include contemporaneous examples from our practice. My
hope is that readers will find in this new edition of Genitourinary Imaging: Case Review
Series a friendly companion that will enhance their educational experience in
genitourinary imaging.
Katarzyna J. Macura, MD, PhD, FACR, FSCBTMR
R e f e r e n c e s
1. Binet EF, Trueblood JH, Macura KJ, Macura RT, Morstad BD, Finkbeiner RV.
Computer-based radiology information system: from floppy disk to CD-ROM.
Radiographics. 1995;15(5):1203–1214.
2. Macura KJ, Macura RT, Morstad BD. Digital case library: a resource for
teaching, learning, and diagnosis support in radiology. Radiographics.
1995;15(1):155–164.Acknowledgment
We are indebted to many people in completing this book. First of all, I thank D r.
D avid Yousem for this opportunity to contribute to the Case Review S eries. I
acknowledge the wonderful contribution to this book provided by D r. A deel S hahid,
our resident, who contributed greatly in writing the cases. I also thank D r. Kristin
Porter for her helpful feedback. I acknowledge the help of my mentors and colleagues
in the D epartment of Radiology and Radiological S cience at the J ohns Hopkins
University S chool of Medicine, particularly my long-time mentor D r. Elliot K.
Fishman, who has been very supportive of academics at J ohns Hopkins, and the other
members of the D iagnostic Radiology division. I acknowledge the support of the
Elsevier team, Ms. Katy Meert and Ms. Lauren Elise Boyle, Content D evelopment
Specialists; Ms. Claire Kramer, Senior Project Manager; and Mr. Donald Scholz, Senior
Content Strategist.
Satomi Kawamoto, MD
Because I teach and learn radiology every day, I am grateful to all my trainees who
over the years have stimulated my growing up as a radiologist with their curiosity and
challenging questions. I have special thanks to fellows who contributed cases to this
book, Drs. Saeid S. Dianat, Luciana G. Matteoni-Athayde, and Kristin K. Porter.
Katarzyna J. Macura, MD, PhD, FACR, FSCBTMROpening RoundCase 1
FIGURE 1-1FIGURE 1-2
History
Premenopausal women are seen for evaluation of pelvic pain.
1. Which of the following are TRUE regarding cyclic changes in the ovary?
(Choose all that apply.)
A. All follicles enlarge in the follicular phase.
B. Hemorrhagic cyst is more likely seen in the secretory phase.
C. Ovarian stroma becomes edematous in the proliferative phase.
D. Corpus luteum is visualized in the luteal phase.
2. Which magnetic resonance imaging (MRI) sequence shows the ovarian
anatomy best?
A. T1-weighted
B. T2-weighted
C. Gradient-echo in-phase
D. Diffusion weighted
3. In acute ovarian torsion, the anatomy of the ovary is altered in which way?
A. Shrinkage of the ovary due to ischemia and infarct
B. Shrinkage of the ovary stroma with enlargement of peripheral follicles
C. Enlargement of the ovary with follicles separated by edematous stroma
D. Enlargement of the ovary due to enlargement of follicles
4. Polycystic ovarian syndrome is suspected on imaging based on which criteria?
A. Enlarged ovaries with T1 bright central stroma and large peripheral
folliclesB. Enlarged ovaries with T2 dark central stroma and small peripheral follicles
C. Numerous ovarian follicles of various sizes and signal intensities
D. Enlarged ovaries with uniform large follicles located in the ovarian stroma
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 1
Normal Ovary Anatomy
1. B and D. The volume and maximal diameter of ovaries and ovarian follicles
and the number of ovarian follicles differ significantly with age but not
between the two ovarian phases of the menstrual cycle. Corpus luteum is seen
in the postovulatory luteal ovarian phase and secretory uterine phase and is
occasionally hemorrhagic. Ovarian stroma becomes edematous with ovarian
torsion and not in response to cyclic changes.
2. B. The zonal anatomy of the ovaries is best seen on MRI on T2-weighted
images and includes the peripheral cortex with lower intensity than the
central medulla. The cortex contains small cysts, follicles at various stages,
corpus luteum, and surface inclusion cysts.
3. C. In ovarian torsion, there is enlargement of the entire ovary where
peripheral follicles are separated by edematous stroma. Individual follicles do
not enlarge. Postcontrast imaging may show absence of enhancement in the
affected ovary from infarction. Unlike ovarian torsion, massive ovarian edema
is not accompanied by infarction, and the ovary remains viable. On imaging,
the ovary shows significant enlargement with edematous stroma of high T2
intensity. Peripherally embedded follicles can help distinguish this condition
from ovarian neoplasm. In massive ovarian edema, there is partial
intermittent torsion of the ovary with obstruction of venous drainage. This
leads to marked enlargement of the ovary due to edema and proliferation of
theca cells in the medulla.
4. B. Polycystic ovary syndrome (PCOS) affects approximately 20% of
premenopausal women. PCOS is usually diagnosed clinically with
hyperandrogenism and anovulation in absence of adrenal or pituitary gland
disease. The diagnostic criteria require at least two of the following three
conditions to be present for the diagnosis of PCOS: (1) oligoovulation or
anovulation, (2) clinical or biochemical signs of hyperandrogenism, and (3)
polycystic ovaries. The criteria for polycystic ovaries include the following: (1)
one or both ovaries demonstrate 12 or more follicles measuring 2 to 9 mm in
diameter, or (2) the ovarian volume exceeds 10 cc. Only one ovary meeting
either of these criteria is sufficient to establish the presence of polycystic
ovaries. On imaging, enlarged ovaries with multiple uniform follicles less
than 1 cm located peripherally and central stroma with low intensity on T2
images (echogenic on ultrasonography) can be observed.
Comment
Menstrual Cycle: Ovarian Cycle
Each menstrual cycle can be divided into three phases on the basis of events in the
ovary (ovarian cycle based on changes in the follicles) and in the uterus (uterine
cycle based on the changes in the endometrium). The ovarian cycle phases are
follicular phase, ovulation, and luteal phase. The uterine menstrual cycle includes
menstruation, proliferative phase, and secretory phase. Both cycles are controlled
by the endocrine system and physiologic hormonal variations.
I n the ovarian cycle, under the follicle-stimulating hormone (FS H) during the
first days of the cycle, a few follicles are stimulated. These follicles, which were
present at birth, are developing in folliculogenesis. Only one dominant follicle willreach maturity (a tertiary or graafian follicle) and will contain the ovum;
nondominant follicles atrophy. Ovulation is the second phase of the ovarian cycle
in which the ovum is released from the mature follicle. The luteinizing hormone
(LH) surges, and under the influence of LH, the ovum matures and the wall of the
fully developed follicle weakens, resulting in release of its oocyte. The luteal phase
is the final phase of the ovarian cycle. D uring the luteal phase, the pituitary
hormones FS H and LH cause the remaining parts of the dominant follicle to
transform into the corpus luteum, which produces progesterone.
Imaging Findings
I n premenopausal women, the ovaries are easily identifiable on pelvic
ultrasonography and MRI because they contain multiple ovarian follicles at
different stages of development. On MRI , T2-weighted images are most useful in
detecting the ovaries and ovarian follicles in women of reproductive age (Figures
S1-1, S1-2, and S1-3). The ovaries are typically seen in the ovarian fossa, anterior to
the internal iliac artery although the position may differ (Figure S1-1). The zonal
anatomy of the ovaries is well seen on MRI T2-weighted images and includes the
peripheral cortex with lower intensity than the central medulla (Figures S 1-1 and
S1-2). The cortex contains small cysts, follicles at various stages, corpus luteum
(Figures S1-4 and S1-5), and surface inclusion cysts.
I n postmenopausal women, ovaries are more difficult to identify because of the
smaller number of ovarian follicles and because of atrophic changes. The mean
volume of both ovaries increases until the age of 31 to 40 years and then
continuously decreases afterward. A lso, the mean volume of the largest ovarian
follicles increases until the age of 41 to 50 years and then decreases in older
women. A lthough, the volume and maximal diameter of ovaries and ovarian
follicles and the number of ovarian follicles differ significantly with age, there is no
change in these parameters between the two phases of the menstrual cycle, except
for a maturing follicle that will rupture with ovulation to release the ovum. These
findings may relate to a cumulative effect of the hormones over the
premenopausal years leading to an increase of the volume of the ovaries up to the
age of 40 years. The postmenopausal decrease of hormonal levels leads to a
subsequent decrease of the volume of the ovaries in elderly women.
References
1. Hauth EA, Jaeger HJ, Libera H, Lange S, Forsting M. Magnetic resonance
imaging of the ovaries of healthy women: determination of normal values.
Acta Radiol. 2006;47(9):986–992.
2. Outwater EK, Mitchell DG. Normal ovaries and functional cysts: MR
appearance. Radiology. 1996;198:397–402.
3. Tamai K, Koyama T, Saga T, et al. MR features of physiologic and benign
conditions of the ovary. Eur Radiol. 2006;16(12):2700–2711.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 258–259.Case 2
FIGURE 2-1FIGURE 2-2
History
Premenopausal woman has pelvic pain.
1. Which conditions should be considered in the differential diagnosis for the
imaging findings presented? (Choose all that apply.)
A. Corpus luteum
B. Ectopic pregnancy
C. Tuboovarian abscess
D. Ovarian neoplasm
2. What hormone is secreted by the structure visualized on imaging in the
figures?
A. Human chorionic gonadotropin (HCG)
B. Luteinizing hormone (LH)
C. Follicle-stimulating hormone (FSH)
D. Progesterone
3. What is a luteal cyst?
A. Functional cyst that develops when the corpus luteum fails to regress
B. Functional cyst resulting from persistence of an unruptured graafian
follicle
C. Fluid accumulation in the corpus albicans
D. Functional cyst developing under influence of gonadotropins
4. What is the ring of fire sign?
A. Peripheral hyperdensity on computed tomography (CT)B. Ringlike enhancement on magnetic resonance imaging
18C. F-fluorodeoxyglucose (FDG)-avid rim on positron emission tomography
(PET)
D. Vascular ring on color Doppler imaging
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 2
Corpus Luteum
1. A, B, and D. Differential diagnosis for a thick-walled mass in the adnexa, with
peripheral vascularity includes a corpus luteum, as illustrated in Figures S2-1
and S2-2, which is located within the ovary; an ectopic pregnancy if the mass
is extraovarian and patient is beta human chorionic gonadotropin (bHCG)
positive; and also an ovarian malignancy, especially metastasis to the ovary
(7% of ovarian tumors are metastases) if the patient has a primary tumor such
as breast cancer, gastrointestinal malignancy, or carcinoid. On PET-CT
imaging a corpus luteum may be FDG avid, and therefore the premenopausal
cancer patient should undergo imaging in the first week of the menstrual
cycle to avoid false-positive FDG uptake in the ovary. A tuboovarian abscess
often appears as a complex multilocular adnexal mass with debris, septations,
and irregular thick walls.
2. D. The corpus luteum assumes temporary endocrine function and secretes
progesterone. It also secretes estrogen to inhibit further release of
gonadotropin-releasing hormone from the hypothalamus and, thus, secretion
of LH and FSH from the anterior pituitary. Progesterone is required for
maintenance of normal pregnancy. If the female becomes pregnant,
continued secretion of progesterone from the corpus luteum is vital to
making the endometrium receptive to implantation of the blastocyst and
supports the early pregnancy by increasing blood flow and reducing the
contractility of the smooth muscle in the uterus. If pregnancy does not occur,
the corpus luteum must regress to allow follicular growth and subsequent
ovulation in the new reproductive cycle.
HCG is a hormone produced by the syncytiotrophoblast, a component of the
fertilized ovum after conception. Following implantation, the
syncytiotrophoblast gives rise to the placenta. Placenta eventually takes over
production of progesterone and the corpus luteum of pregnancy (corpus
luteum graviditatis) can regress.
3. A. A corpus luteum cyst develops when the corpus luteum fails to regress
after ovulation and instead enlarges with or without hemorrhage. The
diagnosis will depend on the menstrual phase. Thus, these cysts are seen at
the end of the luteal phase or during pregnancy. When associated with
pregnancy, most corpus luteum cysts spontaneously involute at the end of the
second trimester. A follicular cyst develops when a dominant follicle does not
rupture or release the ovum and instead grows and turns into a cyst. They
generally resolve spontaneously in two to three menstrual cycles. Theca lutein
cysts are functional ovarian cysts that are typically large, multilocular, and
bilateral. They originate with hyperplasia of the theca interna cells as a result
of excessive amounts of gonadotropins such as bHCG. They are associated
with gestational trophoblastic disease, multifetal pregnancy, and ovarian
hyperstimulation syndrome.
4. D. The ring of fire sign represents a ringlike peripheral hypervascularity in an
adnexal mass on color Doppler imaging, with a characteristic low impedance
high diastolic flow pattern.
This sign can be seen in highly vascular pelvic lesions such as corpus luteum(Figure S2-1) and also in ectopic pregnancy.
Comment
Development of Corpus Luteum
LH surge causes a breakdown of the follicular wall and release of the oocyte at
ovulation. After ovulation, the developing corpus luteum contains a heterogeneous
population of cells that includes steroidogenic luteal cells. The corpus luteum
maintains a high degree of vascularization. Corpus luteum (Latin for “yellow
body”) is yellow as a result of concentrating lipids and yellow pigment from
carotenoids from the diet. The corpus luteum is essential for establishing and
maintaining pregnancy. The corpus luteum secretes progesterone, which is a
steroid hormone responsible for the decidualization of the endometrium.
I f the ovum is fertilized and implantation occurs, the syncytiotrophoblast
secretes the hormone HCG. HCG signals the corpus luteum to continue
progesterone secretion, thereby maintaining the thick endometrium and providing
rich blood vessels in which the zygote(s) can develop. From this point on, the
corpus luteum is called the corpus luteum graviditatis. Once the placenta
develops, it eventually takes over progesterone production, and the corpus luteum
degrades into a corpus albicans at approximately 16 to 20 weeks.
I f the ovum is not fertilized, the corpus luteum stops secreting progesterone and
decays (after approximately 10 days). I t then degenerates into a corpus albicans,
which is fibrous scar tissue.
LH or HCG induces expression of vascular endothelial growth factor, resulting in
proliferation of endothelial cells and neovascularization during luteal development
that results in the corpus luteum’s extensive capillary network.
Imaging Findings
A corpus luteum presents on imaging as a thick-walled and hypervascular lesion
(Figure S2-1) with peripheral enhancement (Figure S2-2). I ntraovarian localization
is the key to a diagnosis (Figures S 2-3, S2-4, S2-5, and S2-6). Occasionally, corpus
luteum has a convoluted wall and may be hemorrhagic (Figures S 2-5 and S2-6).
When there is no conception, the corpus luteum gradually involutes into invisible
on imaging corpus albicans.
Reference
1. Niswender GD, Juengel JL, Silva PJ, Rollyson MK, McIntush EW. Mechanisms
controlling the function and life span of the corpus luteum. Physiol Rev.
2000;80(1):1–29.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 259.Case 3
FIGURE 3-1FIGURE 3-2
History
A 62-year-old man with diabetes and hypertension has scrotal swelling.
1. Which of the following would be included in the differential diagnosis for
imaging findings presented? (Choose all that apply.)
A. Inguinal hernia
B. Liposarcoma
C. Spermatic cord lipoma
D. Undescended testis
2. The inguinal canal in males contains the following structures, EXCEPT:
A. Vas deferens
B. Testicular artery
C. Pampiniform venous plexus
D. Omentum
3. Which statement is TRUE regarding paratesticular tumors?
A. Always benign
B. Majority benign
C. Majority malignant
D. Typically unresectable
4. Which magnetic resonance imaging (MRI) sequence is most specific for
detection of macroscopic fat in a mass?
A. Fast spin echo T2-weighted
B. T1-weighted with fat suppressionC. Gradient echo in and out-of-phase imaging
D. Inversion recovery (IR) imaging
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 3
Inguinal Canal Lipoma
1. A, B, and C. Inguinal hernia, liposarcoma, spermatic cord lipoma are on the
differential diagnosis list for an extratesticular mass in the region of the
inguinal canal and scrotum. This patient’s testis is visualized in the anatomic
position in the scrotum; therefore it is not undescended.
2. D. The inguinal canal in males contains the spermatic cord that consists of the
vas deferens, the testicular artery, the pampiniform venous plexus, the
lymphatic vessels of the testis, and nerves. The inguinal canal does not
contain omentum; however, because it connects the pelvic cavity with the
scrotum, omentum can herniate into the inguinal canal, which can lead to
omental torsion.
3. B. Paratesticular tumors most commonly arise from the spermatic cord. It has
been estimated that 70% of paratesticular tumors are benign and 30% are
malignant.
4. B. The most specific MRI sequence for the detection of macroscopic fat is
T1weighted imaging with frequency selective fat suppression. On T1-weighted
images macroscopic fat has a hyperintense signal and can be suppressed by
selectively exciting fat protons with a narrow radiofrequency excitation pulse.
Fast spin echo T2-weighted images typically show macroscopic fat as tissue
with a hyperintense signal that can be difficult to distinguish from aqueous
tissues. Chemical shift imaging with gradient echo in and out-of-phase
imaging is useful for detection of intracellular microscopic fat (i.e., adrenal
adenoma) but not for macroscopic fat. IR imaging is not specific in that it has
the potential to suppress signal from all tissues with T1 values similar to
those of fat, such as blood products or gadolinium-enhanced tissues.
However, because frequency selective fat suppression is susceptible to
magnetic field inhomogeneity in some instances, namely hip arthroplasty, IR
techniques may need to be used in place of frequency selective fat
suppression to achieve a diagnostic quality of imaging when detection of
macroscopic lipid is desired.
Comment
Etiology
Lipoma is the most common benign neoplasm of the paratesticular tissues and
spermatic cord, comprising 45% of paratesticular masses. D uring inguinal hernia
repairs, incidental lipomas are commonly found. The prevalence of inguinal canal
lipoma, a discrete mass of fat, on groin dissections performed in adult males after
death was 75%. A bout 70% displayed a characteristic shape, having an elongated,
pedunculated form with a narrow neck at the deep inguinal ring and a wider,
bulbous distal end. A bout 50% were larger than 4 cm in length. S ome dissections
showed distortion of the proximal spermatic cord but no direct involvement of the
spermatic cord. These masses consist of mature adipose tissue, fibrous tissue, and
blood vessels ranging from capillaries to large muscular arteries. Most of them
contain a loose fibrous capsule.
Because the inguinal canal lipoma is a common feature with high prevalence in
the adult male population, this suggests a developmental etiology. The hypothesis
is that incomplete regression of the abdominal gubernaculum (embryonicstructure aNaching to the caudal end of the male gonads that aids in the descent of
the testes as they ultimately pass through the inguinal canal) in response to fetal
hormone levels leads to fat deposition within the gubernaculum remnant, and this
persists in the adult males as the inguinal canal fat mass or surgical “lipoma.”
Differential Diagnosis
Extratesticular neoplasms represent a heterogeneous group of lesions that affect
patients of all ages, with the prevalence of benign lesions at 70%. The spermatic
cord is the primary site of origin of extratesticular tumors in 75% to 90% of the
cases. They can also arise from the epididymis or the mesenchymal sheaths that
surround the testicle. The clinical manifestation of an inguinal mass is typically a
painless inguinal or scrotal swelling. I t is difficult to differentiate between benign
and malignant lesions clinically. Features suggestive of malignancy include rapid
growth, large size, and symptomatic presentation. While common inguinoscrotal
swellings (hernias and hydroceles) can be diagnosed on clinical examination, all
atypical swellings should be further investigated with imaging before surgical
exploration.
Ultrasonography is the modality of choice to detect and evaluate paratesticular
masses because it has a high sensitivity for the characterization of the origin of
lesions as intratesticular versus extratesticular. The precise definition of a
paratesticular mass is usually difficult by sonographic appearance alone.
Computed tomography (CT) and MRI are helpful in distinguishing a primary
spermatic cord tumor from a retroperitoneal or peritoneal process extending into
the scrotum. CT allows the determination of the mass size and extent and is
typically used for staging liposarcomas, while MR can give a more precise anatomic
localization and tissue characterization (i.e., faNy composition) (Figures S 3-1, S3-2,
S3-3, and S3-4). Both T1-weighted and T2-weighted sequences on MRI should be
performed, and fat-suppressed sequence should also be used in cases in which a
lipoma or liposarcoma is a consideration (Figures S 3-1 and S3-4). A lthough there
are some sonographic characteristics that have been identified for lipomas
(homogeneous hyperechoic circumscribed mass), indeterminate solid masses
(Figures S 3-5 and S3-6) may require follow-up MRI for problem solving and tissue
characterization. CT and MRI may also help define the best surgical approach
before resection.
References
1. Heller CA, Marucci DD, Dunn T, et al. Inguinal canal “lipoma”. Clin Anat.
2002;15(4):280–285.
2. Vagnoni V, Brunocilla E, Schiavina R, et al. Inguinal canal tumors of
adulthood. Anticancer Res. 2013;33(6):2361–2368.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 315.Case 4
FIGURE 4-1FIGURE 4-2
History
A 43-year-old woman has an incidentally discovered mass by computed
tomography (CT).
1. Which of the following would be included in the differential diagnosis for the
imaging findings presented? (Choose all that apply.)
A. Retroperitoneal liposarcoma
B. Adrenal myelolipoma
C. Adrenal adenoma
D. Renal angiomyolipoma
2. Which of the following is the most appropriate next diagnostic examination
for this lesion?
A. No further diagnostic workup is necessary
B. Indium (In)–111 pentetreotide imaging (Octreoscan)
C. Adrenal vein sampling
D. Percutaneous biopsy
3. Which of the following is the most common presentation of this lesion?
A. Hypertension
B. Acute hemorrhage
C. Hematuria
D. Incidentally found on imaging studies
4. Which of the following is correct regarding the lesion seen in the figures?
A. The lesion of the same pathologic entity exclusively occurs in the adrenalglands.
B. Calcifications are uncommon and seen in less than 5% of the lesion.
C. It contains mature adipose tissue and hematopoietic tissue.
D. It has malignant potential.
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 4
Adrenal Myelolipoma
1. A, B, and D. The presence of macroscopic fat (e.g., less than − 30 Hounsfield
unit [HU] on CT) in the tumor, which originates from the adrenal gland, is
virtually diagnostic of myelolipoma. If the adrenal origin of the mass cannot
be confirmed, renal angiomyolipoma and retroperitoneal liposarcoma should
be considered, but they are less likely in this case because there are no
findings to suggest that it is an extraadrenal origin. Lipid-rich adrenal
adenoma can be characterized on noncontrast CT as a low-density lesion with
CT attenuation values between − 10 and 10 HU, but usually it does not show a
large amount of macroscopic fat.
2. A. Macroscopic fat in an adrenal mass is virtually pathognomonic for
myelolipoma. Most myelolipomas are hormonally nonfunctional. If the
diagnosis is established by CT or magnetic resonance imaging (MRI), further
workup is usually not required.
3. D. Adrenal myelolipomas are usually asymptomatic and are discovered
incidentally. However, they may present with flank discomfort or pain
because of mass effect or hemorrhage.
4. C. Adrenal myelolipoma is composed of mature adipose tissue and
hematopoietic tissue in varying proportions. Myelolipomas may occur in
extraadrenal sites but are significantly less common than their adrenal
counterpart. Approximately 25% to 30% of adrenal myelolipomas have
calcification. It is a benign tumor and has no malignant potential.
Comment
Background
A drenal myelolipoma is a rare benign neoplasm and is composed of mature
adipose tissue and hematopoietic tissue in varying proportions. I ncidence of
adrenal myelolipomas is estimated to be 0.08% to 0.2% based on autopsy studies.
Myelolipomas may occur in extraadrenal sites but are significantly less common
than their adrenal counterpart and typically occur in the retroperitoneum.
Clinical Presentation
Most adrenal myelolipomas are asymptomatic and discovered incidentally on
imaging studies. They may rarely cause symptoms, such as abdominal or flank
pain because of mass effect due to large size or intratumoral or retroperitoneal
hemorrhage. The great majority of adrenal myelolipomas are hormonally inactive
but rarely associated with endocrine dysfunction (Cushing syndrome, Conn
syndrome).
Imaging Findings
Most myelolipomas are less than 5 cm at presentation but tumors greater than
20 cm have been reported. There may be variable amounts of fat within the adrenal
myelolipoma, ranging from only a few small regions of fat in a predominantly soft
tissue density mass to nearly entirely composed of faNy tissue as seen in this case.
D etection of macroscopic fat within an adrenal mass on imaging is virtually
diagnostic of a myelolipoma. However, myelolipomatous foci in adrenal adenoma,
which has macroscopic fat, have been reported. A lso, very rarely, adrenocortical
carcinoma and adrenal metastasis containing macroscopic fat have been reported.
On CT, adrenal myelolipoma is seen as a well-defined fat-containing mass (FiguresS4-1, S4-2, and S4-3) but is often heterogeneous in aNenuation because of the
mixed adipose and myeloid tissue. The macroscopic fatty component is low density
on CT, usually less than − 30 HU, and often as low as − 100 HU. Calcifications may
be seen in 25% to 30% of myelolipomas, particularly when hemorrhage has
occurred. I ntratumoral hemorrhage may modify the classic appearance of the
tumor. On MRI , macroscopic fat component appears hyperintense on T1-weighted
imaging. With MRI , macroscopic fat is best detected with frequency selective
fatsuppressed sequences. On ultrasonography, myelolipoma is generally seen as a
suprarenal mass of increased echogenicity. A hypoechoic component may be seen
representing the myeloid element.
Management
I f the diagnosis of myelolipoma is established by characteristic imaging features,
further workup is usually not required. Typically, adrenal myelolipomas can be
conservatively managed. I f the patient is symptomatic, surgical removal is
indicated. I f the nonfaNy component predominates and imaging findings are
indeterminate, it should be managed like other non–fat-containing adrenal
masses.
References
1. Caoili EM, Korobkin M, Francis IR, et al. Adrenal masses: characterization
with combined unenhanced and delayed enhanced CT. Radiology.
2002;222(3):629–633.
2. Guo YK, Yang ZG, Li Y, et al. Uncommon adrenal masses: CT and MRI
features with histopathologic correlation. Eur J Radiol. 2007;62(3):359–370.
3. Kenney PJ, Wagner BJ, Rao P, Heffess CS. Myelolipoma: CT and pathologic
features. Radiology. 1998;208(1):87–95.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 368–369.Case 5
FIGURE 5-1FIGURE 5-2
History
A 58-year-old man has a history of known renal disease and previous episodes of
flank pain. The patient has had renal transplant in the right iliac fossa.
1. Which of the following would be included in the differential diagnosis for the
imaging findings presented? (Choose all that apply.)
A. Multiple simple cysts
B. Autosomal dominant polycystic kidney disease (ADPKD)
C. Von Hippel-Lindau disease
D. Acquired renal cystic disease of dialysis
2. Which one of the following conditions is most likely associated with the
illustrated disease?
A. Renal angiomyolipoma
B. Renal cell carcinoma
C. Hepatic cysts
D. Hepatic fibrosis
3. Which of the following statements is correct regarding renal cysts in the
illustrated disease?
A. Renal cysts are typically uniform in size and less than 1 cm.
B. Unilateral involvement of renal cysts is common.
C. Complicated cysts are often seen as hyperattenuating cysts on computed
tomography (CT).
D. Renal cysts are predominantly detected in the medulla of the kidneys andsparingly in the outer cortex.
4. Which one of the following statements is correct regarding the illustrated
disease?
A. Intracranial aneurysm is seen in approximately 50% of the patients with
this disease.
B. Patients with this disease usually present in the first decade of life.
C. Renal function is well preserved, and patients rarely develop end-stage
renal disease.
D. Kidneys are usually significantly enlarged.
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 5
Autosomal Dominant Polycystic Kidney Disease (ADPKD)
1. A, B, and C. Bilateral renal enlargement caused by innumerable cysts
replacing renal parenchyma is characteristic of ADPKD. Multiple bilateral
simple cysts may resemble ADPKD, but cysts are usually fewer in number
and are not associated with renal enlargement. Multiple renal cysts are seen
in 75% of the cases of von Hippel-Lindau disease, but cysts are usually smaller
in number. In acquired renal cystic disease, kidneys are usually small, and
cysts are small and fewer in number.
2. C. Hepatic cysts are most frequently seen as extrarenal cysts in patients with
ADPKD and are seen in 54% to 74% of these patients. Patients with ADPKD
are not at increased risk of having renal angiomyolipomas (associated with
tuberous sclerosis), renal cell carcinomas (associated with von Hippel-Lindau
disease), or hepatic fibrosis (associated with autosomal recessive polycystic
kidney disease).
3. C. Most of the cysts in ADPKD are simple cysts, but complicated cysts from
hemorrhage or infection are seen as hyperattenuating cysts on CT. In
ADPKD, innumerable cysts of variable size (from barely visible to several
centimeters) can develop anywhere along the nephron and are seen both in
the cortex and medulla. Although rare cases of unilateral ADPKD are
reported, both kidneys are typically affected.
4. D. Massive bilateral renal enlargement caused by innumerable cysts is
characteristic of ADPKD. Intracranial aneurysm is associated with 10% to 15%
of the patients with ADPKD. Patients with ADPKD usually present in the
third or fourth decades of life, and often result in progressive deterioration of
renal function leading to end-stage renal disease.
Comment
Clinical Presentations
A D PKD is the most common hereditary renal cystic disease. A D PKD results in
progressive deterioration of renal function, and about 45% of patients have
endstage renal disease. A D PKD is caused by mutations of either polycystic kidney
disease 1 gene (PKD1) (which encodes polycystin-1) on chromosome 16 or PKD2
(which encodes polycystin-2) on chromosome 4.
Patients with A D PKD often present in the third or fourth decades of life with
hematuria, hypertension, and renal insufficiency. They may have flank pain due to
complicated cysts with hemorrhage or infection, ureteral stone, and progressive
enlargement of renal cysts. A D PKD is associated with intracranial aneurysm in
approximately 10% of the patients. Patients with A D PKD are not at increased risk
of having renal malignancy.
Imaging Findings
Bilateral renal enlargement caused by innumerable cysts is characteristic of
ADPKD (Figures S 5-1, S5-2, S5-3, S5-4, and S5-5). The cysts are variable in size and
seen in both cortical and medullary locations. Most of the cysts are simple cysts;
however, complicated cysts secondary to hemorrhage or infection are often seen as
hyperaNenuating on CT (Figures S 5-1 and S5-2). A cute hemorrhage causes
increased internal density of a cyst, but as blood liquefies and organizes,
aNenuation values decrease over time. With infection, cyst wall thickening andpericystic inflammation may be seen. Complicated cysts are typically seen on
T1weighted MR images, and hypointense on T2-weighted MR images (FigureS 5-3),
but the appearance of hemorrhagic cyst varies secondary to various stages of
evolution of intracystic hemorrhage. I ntracystic debris on ultrasonography
suggests a hemorrhagic or infected cyst (Figure S5-4). Cyst wall calcification is
common in A D PKD and may be secondary to hemorrhage or infection. F(igures
S5-1 and S5-2). Extrarenal cysts are often seen in the liver (54% to 74% of patients),
pancreas (10%), spleen, ovaries, and testes.
Differential Diagnosis
Multiple renal cysts are seen in other conditions, including multiple bilateral
simple cysts (fewer number of cysts, no renal enlargement), acquired renal cystic
disease of dialysis (small kidneys, smaller size, and fewer number of cysts), and
syndromes associated with multiple renal cysts such as tuberous sclerosis and von
Hippel-Lindau disease.
Management
Management of A D PKD is currently directed to blood pressure reduction and
treatment of complications. I maging studies are used to monitor cyst volumes,
which reflect the severity of disease.
References
1. Bae KT, Grantham JJ. Imaging for the prognosis of autosomal dominant
polycystic kidney disease. Nat Rev Nephrol. 2010;6(2):96–106.
2. Katabathina VS, Kota G, Dasyam AK, Shanbhogue AK, Prasad SR. Adult renal
cystic disease: a genetic, biological, and developmental primer. Radiographics.
2010;30(6):1509–1523.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 109–111, 144–147.Case 6
FIGURE 6-1FIGURE 6-2
History
A 30-year-old woman has right upper quadrant pain. Pelvic mass was incidentally
found by computed tomography (CT).
1. Which of the following would be included in the differential diagnosis for the
imaging findings presented? (Choose all that apply.)
A. Cystadenocarcinoma of the ovary
B. Lipoleiomyoma of the uterus
C. Mature cystic teratoma of the ovary
D. Liposarcoma
2. The following findings can be seen on ultrasonography for this type of tumor,
EXCEPT:
A. Fat-fluid level
B. Tip of iceberg sign
C. Hypoechoic mass with increased posterior through transmission, with
internal lacelike, fine reticular appearance
D. Dermoid mesh
3. Which of the following terms is used to describe mural nodule on the internal
surface of the mass shown in Figures S6-1 and S6-2?
A. Aschoff nodule
B. Pseudopolyp
C. Zuckerkandl nodule
D. Rokitansky nodule
4. Which of the following is the most common complication of this type of tumor
shown in Figures 6-1 and 6-2?
A. Malignant transformationB. Rupture of the mass
C. Torsion
D. Anemia
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 6
Mature Cystic Teratoma of the Ovary
1. C and D. CT shows well-defined ovarian mass containing large amount of fat
and solid mural nodule containing calcifications, which is characteristic of
mature cystic teratoma. Other differential diagnoses of fat-containing pelvic
mass in women include pelvic lipoma/liposarcoma and uncommon
lipomatous uterine tumor such as uterine lipoleiomyoma. The key to
differentiate these lesions is to identify the organ of origin. Pelvic
liposarcomas most commonly occur in the retroperitoneum, but
intraperitoneal liposarcoma may also occur. Uterine lipoleiomyomas are
uncommon benign uterine neoplasms, similar to uterine leiomyomas in
clinical presentation and course.
2. C. Hypoechoic mass with increased posterior through transmission, with
internal lacelike, reticular appearance is a typical sonographic finding of a
hemorrhagic ovarian cyst.
3. D. Mature cystic teratoma is typically seen as a cystic adnexal mass with some
mural nodules. Such a mural nodule is called Rokitansky nodule or dermoid
plug. Rokitansky nodule (also called a dermoid plug). Hair, bone, or teeth
tend to be located within this nodule. On ultrasonography, it is seen as a
densely echogenic nodule projecting into the cyst lumen often associated with
shadowing caused by a calcification, sebum, or hair conglomerate.
4. C. The most common complication associated with a mature cystic teratoma of
the ovary is ovarian torsion, with a reported incidence of 3.2% to 16%.
Comment
Pathology
Mature cystic teratoma, often called dermoid cyst, is the most common germ cell
neoplasm of the ovary. These cystic tumors are composed of well-differentiated
derivations from at least two of the three germ cell layers (ectoderm, mesoderm,
and endoderm). They are unilocular in 88% of the cases, and the wall of the cyst is
lined by squamous epithelium. There is often a raised protuberance or mural
nodule projecting into the cyst cavity, known as Rokitansky nodule (or dermoid
plug). It often contains hair and other dermal appendages, bone, and teeth.
Clinical Presentation
These tumors are usually asymptomatic and often incidentally discovered in young
women. The mean patient age is 30 years. The tumors are bilateral in 10% to 15% of
cases.
The most common complication associated with these tumors is ovarian torsion,
with a reported incidence of 3.2% to 16%. Rupture is an uncommon complication
(1.2% to 3.8%) and may lead to chemical peritonitis. Malignant transformation
rarely occurs (1% to 2%), usually in large tumors in postmenopausal women, with
squamous cell carcinomas being the most common. The Rokitansky nodule is a
frequent site of malignant transformation. Other rare complications include
infection (
Imaging Findings
Ultrasonography appearance is variable but most commonly is a cystic lesion with
a densely echogenic tubercle (Rokitansky nodule) projecting into the cyst lumen
(Figures S 6-2 and S6-6). This echogenic mass is often associated with extensiveacoustic shadowing obscuring the deep structure and is called “tip of iceberg
sign.” Cyst cavity is often diffusely or partially echogenic associated with posterior
sound aNenuation due to sebaceous material and hair within the cyst cavity.
However, pure sebum within the cyst cavity may be hypoechoic or anechoic.
Multiple linear echogenic bands caused by hair strands floating within the cyst
may be seen and are called “dermoid mesh.”
At CT, fat aNenuation within a cyst, with or without calcification, is diagnostic of
mature cystic teratoma (Figures S 6-1, S6-3, S6-4, and S6-5). Fat is seen in 93% of
cases and teeth or other calcifications in 56% by CT.
On magnetic resonance imaging (MRI ), sebaceous component of mature cystic
teratoma follows signal intensity of fat. Fat-fluid level due to sebum layered on
serous fluid may be seen on ultrasonography, CT, or MRI.
Management
These cysts are typically resected because of the risk complications, including
ovarian torsion, rupture, and malignant transformation. S imple cystectomy may be
performed rather than salpingo-oophorectomy to preserve the ovarian tissue for
young patients.
References
1. Choudhary S, Fasih N, Mc Innes M, Marginean C. Imaging of ovarian
teratomas: appearances and complications. J Med Imaging Radiat Oncol.
2009;53:480–488.
2. Outwater EK, Siegelman ES, Hunt JL. Ovarian teratomas: tumor types and
imaging characteristics. Radiographics. 2001;21(2):475–490.
3. Saba L, Guerriero S, Sulcis R, Virgilio B, Melis G, Mallarini G. Mature and
immature ovarian teratomas: CT, US and MR imaging characteristics. Eur J
Radiol. 2009;72(3):454–463.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 289, 290.Case 7
FIGURE 7-1FIGURE 7-2
History
A 76-year-old man has fever and urinary tract infection.
1. What are the risk factors that can lead to development of the illustrated
disease? (Choose all that apply.)
A. Indwelling catheters
B. Recent prostate biopsy
C. Instrumentation of the lower urinary tract
D. Diabetes
2. In the antibiotic era, what are the most likely bacteria involved in the
illustrated disease?
A. Neisseria gonorrhoeae
B. Staphylococcus aureus
C. Mycobacterium tuberculosis
D. Escherichia coli
3. Which pathogen can cause granulomatous prostatitis?
A. Actinomycosis
B. Bacillus Calmette-Guérin (BCG)
C. Schistosomiasis
D. Syphilis
4. What is the best treatment option for the illustrated disease?
A. Observation and symptomatic treatment
B. Parenteral antibiotics
C. Transperineal drainageD. Parenteral antibiotics and drainage
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 7
Prostate Abscess
1. A, B, C, and D. Indwelling catheters, a recent prostate biopsy, and
instrumentation of the lower urinary tract can be risk factors for prostatic
abscess. Prostatic abscess mainly affects diabetic and immunosuppressed
patients.
2. D. In the preantibiotic era, N. gonorrhoeae was the primary organism
responsible in 75% of prostate abscess cases. However, in the antibiotic era,
gram-negative bacilli, mainly E. coli, have caused about 60% to 80% of cases.
Other significant pathogens include Pseudomonas species and Staphylococcus
species.
3. B. Granulomatous prostatitis is a form of focal prostatitis that can mimic
prostate carcinoma clinically and on transrectal sonograms and magnetic
resonance imaging (MRI). Results of biopsy reveal either caseating or
noncaseating granulomas. The most common form of specific granulomatous
prostatitis is caused by BCG, which is used for immunotherapy of superficial
bladder cancer.
4. D. Percutaneous transperineal or transrectal drainage with ultrasonography
guidance is the first choice for therapy accompanied by administration of
parenteral broad-spectrum antibiotics. When not adequately treated, or when
treatment is delayed, prostatic abscess can progress to sepsis and death.
Comment
Pathogenesis
Prostatic abscess is an uncommon condition because of the wide use of
broadspectrum antibiotics in patients with lower urinary tract symptoms. I t is often
difficult to differentiate clinically from acute prostatitis. Patients usually have
typical signs and symptoms of prostatitis, including fever, chills, urinary frequency
and urgency, perineal and low back pain, difficulty voiding, dysuria, and
hematuria. When not adequately treated or when treatment is delayed, prostatic
abscess can progress to sepsis and death. Historically, the common infecting
organisms were N . gonorrhoeae, S. aureus, and M. tuberculosis. However, more
recently, gram-negative bacteria, such as E. coli, have caused about 60% to 80% of
cases. I t is thought that the retrograde flow of contaminated urine within the
prostate during micturition is the most prevalent pathogenic factor. I ndwelling
catheters, a recent prostate biopsy, and instrumentation of the lower urinary tract
can be risk factors for prostatic abscess. Bacterial hematogenous spread from
distant foci of infection has been described to include sources such as respiratory
infection, appendicitis and diverticulitis, and skin infections. Prostatic abscess
mainly affects diabetic and immunosuppressed patients.
Imaging Findings
Prostatic abscess results from focal accumulation of pus within the prostate gland.
The findings on a digital rectal examination can often detect a fluctuant mass. On
transrectal ultrasonography, a complex cystic hypoechoic mass with well-defined
and thick walls may be seen. A multilocular intraprostatic fluid collection with
thick walls and irregular enhancing septations can be seen on MRI and computed
tomography (CT), replacing the normal prostate tissue between the bladder and
rectum (Figures S 7-1, S7-2, S7-3, S7-4, S7-5, and S7-6). On MRI , variable internalsignal characteristics are seen related to accumulated debris. CT and MRI can help
to detect contiguous spread of infection to nearby organs by detection of
inflammatory enhancement of the surrounding tissues.
Management
Treatment options for prostatic abscess include parenteral broad-spectrum
antibiotic administration and abscess drainage. D rainage may be performed by
ultrasonography-guided transrectal or transperineal route, digital-guided puncture
and drainage by perineal route, transurethral incision of the prostate, or open
perineal drainage. There is a preference for minimally invasive procedures that
may be performed under local anesthesia or sedation with ultrasonography
guidance, which is repeated if necessary.
References
1. Barozzi L, Pavlica P, Menchi I, De Matteis M, Canepari M. Prostatic abscess:
diagnosis and treatment. AJR Am J Roentgenol. 1998;170(3):753–757.
2. Jang K, Lee DH, Lee SH, Chung BH. Treatment of prostatic abscess: case
collection and comparison of treatment methods. Korean J Urol.
2012;53(12):860–864.
3. Oliveira P, Andrade JA, Porto HC, Filho JE, Vinhaes AF. Diagnosis and
treatment of prostatic abscess. Int Braz J Urol. 2003;29(1):30–34.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 343–345.Case 8
FIGURE 8-1
FIGURE 8-2
History
A 48-year-old man has sudden-onset sharp right flank pain with nausea anddiaphoresis.
1. Which of the following would be in the differential diagnosis for the imaging
findings presented? (Choose all that apply.)
A. Retroperitoneal fibrosis
B. Obstructing calculus at ureterovesical junction
C. Calculus that has recently passed into the bladder
D. Retroperitoneal hematoma
2. The following computed tomography (CT) or sonographic findings are seen
with urinary calculus, EXCEPT:
A. Tail sign on unenhanced CT
B. Rim sign on unenhanced CT
C. Twinkling artifact on color Doppler sonography
D. Absent ureteral jet on color Doppler sonography
3. The following findings are indirect CT finding of acute obstructing ureteral
calculus, EXCEPT:
A. Perinephric stranding
B. Renal atrophy
C. Enlarged kidney
D. Hydronephrosis and hydroureter
4. Which of the following types of calculus is invisible on CT?
A. Calcium phosphate stone
B. Uric acid stone
C. Indinavir stone
D. Cystine stone
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 8
Acute Obstructing Ureteral Calculus
1. B and C. CT shows hydronephrosis/hydroureter to the level of the small
calculus at the right ureterovesical junction associated with
perinephric/periureteral edema and right renal swelling. An obstructing stone
at the ureteral insertion to the bladder can be difficult to differentiate from a
stone that has recently passed into the bladder. In this case, ultrasonography
shows the stone is within the ureterovesical junction.
2. A. The “tail sign” (also called “comet sign” or “comet tail sign”) is a linear
soft-tissue attenuation structure that extends to the calcification on
unenhanced CT, representing the vein associated with a phlebolith. The “rim
sign” (also called “soft tissue rim sign”) is a soft-tissue ring surrounding the
calcification representing the edematous ureteral wall on unenhanced CT,
which is in favor of a stone.
3. B. Imaging studies may show direct finding (obstructing urinary calculus) as
well as indirect findings (hydronephrosis and hydroureter to the level of the
obstructing stone, perinephric/periureteral edema, and swollen kidney). The
degree of perinephric edema correlates to the degree of functional
obstruction. Renal atrophy can be seen in chronic urinary obstruction, but
this is not associated with acute renal colic.
4. C. Almost all urinary stones are seen as a high attenuation focus on CT.
However, indinavir stone in patients with human immunodeficiency virus
(HIV) infection receiving indinavir (antiretroviral drug) may not be visible on
CT.
Comment
Background
Renal colic is defined as acute pain by obstructing ureteral calculus. The common
locations for obstruction by a stone are the ureteropelvic junction, the pelvic brim
where the ureter crosses the iliac vessels, and the ureterovesical junction.
Imaging Findings
I maging can provide information regarding the presence, size, location of the
stone, degree of obstruction, potential complications, and, in some cases,
alternative diagnosis for the cause of pain.
Unenhanced CT is the current imaging modality of choice because of its high
sensitivity (95%), specificity (98%), and accuracy (97%) in diagnosing urolithiasis in
patients presenting with acute flank pain. I t shows direct findings (obstructing
urinary calculus) and secondary findings (hydronephrosis/hydroureter,
perinephric/periureteral edema, and swollen kidney) (Figures S 8-1, S8-2, S8-3, and
S8-4).
Ultrasonography (Figures S 8-5 and S8-6) is recommended as the initial imaging
modality in pregnant women and children, although it is poor for detecting stones
in the midureter. A calculus appears as an echogenic focus associated with
posterior acoustic shadowing. Twinkling or color-comet-tail artifact is associated
with calculus on color D oppler imaging. A bsence of a ureteral jet from the affected
side is another valuable indirect sign of obstruction (Figure S8-6).
Magnetic resonance imaging (MRI ) or MR urography may be used especially
when radiation dose is of concern. Calculi on MRI are of low intensity.Computed Tomography Pitfalls
I t is occasionally difficult to distinguish between nonobstructing distal ureteral
calculi and pelvic phleboliths on unenhanced CT. A soft-tissue “rim sign” (a
softtissue ring surrounding the calcification representing the edematous ureteral wall)
is in favor of a stone. The “tail sign” (a linear soft-tissue aNenuation that extends to
the calcification representing the vein associated with phlebolith) is in favor of a
phlebolith (Figure S8-2).
A lmost all urinary stones are seen as a high aNenuation focus on CT. However,
rarely, stones may be radiolucent on CT, including pure matrix stones in patients
with urease-producing bacterial infection and indinavir-induced stones in patients
with HI V infection who are on indinavir (antiretroviral drug; protease inhibitor)
therapy.
Management
Treatment options depend on the stone size and location and duration of the
symptoms. The majority of small (
References
1. Miller JC, Maher MM, Grocela JA, Thrall JH, Lee SI. Imaging for renal colic
and hematuria. J Am Coll Radiol. 2006;3(10):814–817.
2. Reddy S. State of the art trends in imaging renal of colic. Emerg Radiol.
2008;15(4):217–225.
3. Taourel P, Thuret R, Hoquet MD, Doyon FC, Merigeaud S, Delabrousse E.
Computed tomography in the nontraumatic renal causes of acute flank pain.
Semin Ultrasound CT MR. 2008;29(5):341–352.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 187–191.Case 9
FIGURE 9-1FIGURE 9-2
History
A 68-year-old woman has incidentally found a 2.5-cm renal mass. Computed
tomography (CT) aNenuation of this mass is 82 HU on noncontrast CT F(igure 9-1),
84 HU on corticomedullary phase CT, and 82 HU on excretory phase CT (Figure
92).
1. Which of the following would be in the differential diagnosis for the imaging
findings presented? (Choose all that apply.)
A. Renal cell carcinoma
B. Hyperattenuating cyst
C. Angiomyolipoma with minimal fat
D. Abscess
2. Which of the following is the most appropriate category in Bosniak
classification for the mass seen in the figures?
A. Bosniak category II
B. Bosniak category IIF
C. Bosniak category III
D. Bosniak category IV
3. For a confident diagnosis of a hyperattenuating cyst, the renal mass should
have all of the following CT findings, EXCEPT:
A. Contrast enhancement ≤ 10 Hounsfield unit (HU) after administration of
intravenous contrast material
B. Completely homogeneous attenuation even with a narrow window settingC. Smooth and sharply marginated
D. Completely intrarenal location
4. Which of the following is TRUE regarding hyperattenuating renal cysts?
A. A nonenhancing, homogeneous, hyperattenuating renal mass that
measures greater than 3 cm is classified as a Bosniak category III lesion.
B. If internal echo is seen at ultrasonography, it is not a hyperattenuating
cyst.
C. Homogeneous hyperattenuating renal masses that have attenuation
greater than 70 HU on unenhanced CT are almost always benign.
D. At magnetic resonance imaging (MRI), hyperattenuating cysts usually
have low-signal intensity on T1-weighted images.
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 9
Hyperattenuating Renal Cyst
1. B. CT shows two small (≤ 3 cm) cysts. They do not enhance, and at least one
quarter of its wall is abutting perinephric fat. These findings are compatible
with a hyperattenuating cyst. Renal cell carcinoma and angiomyolipoma with
minimal fat may appear hyperattenuating on unenhanced CT, but they
demonstrate contrast enhancement.
2. A. This mass is compatible with a hyperattenuating cyst and is classified as
Bosniak category II.
3. D. At least one quarter of a hyperattenuating cyst’s wall should abut
perinephric fat so that its wall can be assessed as thin and smooth.
4. C. A study found that a homogeneous hyperattenuating renal mass measuring
≥ 70 HU on unenhanced CT has a greater than 99.9% chance of being a
hyperattenuating cyst. Nonenhancing hyperattenuating renal masses that
measure greater than 3 cm or that are in a completely intrarenal location are
classified as Bosniak category IIF lesions. At ultrasonography, they may
appear sonolucent or may have internal echoes because of the thick nature of
the contents. At MRI, hyperattenuating cysts usually have high-signal
intensity on T1-weighted images due to hemorrhage or high-protein content.
Comment
Background
Benign renal cysts may contain high-aNenuation fluid (> 20 HU) and are referred to
as hyperaNenuating (or hyperdense) cysts. This may be a result of blood, or its
breakdown products, or high-protein content. They are included in the Bosniak
category II.
Imaging Findings
For a diagnosis of a hyperaNenuating cyst to be made with confidence, the mass
must be small (≤ 3 cm), smooth and sharply marginated, homogeneously
hyperaNenuating, and nonenhancing (increased aNenuation ≤ 10 HU after
administration of intravenous contrast material) (Figures S 9-1, S9-2, S9-3, S9-4,
S95, and S9-6). At least one quarter of a cyst wall should abut perinephric fat so that
its wall can be assessed as thin and smooth.
J onisch and associates found that a homogeneous hyperaNenuating renal mass
measuring ≥ 70 HU on unenhanced CT has a greater than 99.9% chance of being a
hyperaNenuating cyst. I f a hyperaNenuating mass is depicted only on enhanced
CT, delayed CT (at least 15 minutes) can be performed to exclude
“deenhancement” (decrease in attenuation ≥ 15 HU over time indicates a solid lesion).
At ultrasonography, hyperaNenuating cysts may appear as simple cysts or may
have internal echoes and decreased through-transmission. At MRI , they usually
have high-signal intensity on T1-weighted images.
Bosniak Classification (I, II, IIF)
The Bosniak renal cyst classification system is based on morphologic and
enhancement characteristics of cystic lesions with precontrast and postcontrast CT
or MRI and is a useful guide for treatment. Bosniak category I cysts have a
hairlinethin wall, no septa or calcifications, no solid components, water aNenuation, and
no enhancement. Bosniak category I I includes hyperaNenuating cysts, cysts with
few hairline-thin septa with or without perceived (not measurable) enhancement,fine calcifications, or short segment or slightly thickened calcifications in the wall
or septa. Bosniak I I F cysts are associated with calcification that may be thick and
nodular but no measurable enhancement. HyperaNenuating cysts that are
completely intrarenal or greater than 3 cm are classified as Bosniak I I F (seeC ases
59 and 115 for discussion of other Bosniak categories).
Management
Bosniak category I and I I cysts are benign and do not require follow-up. Bosniak
category I I F cysts require follow-up, typically at 6 and 12 months, then yearly for 5
years.
References
1. Israel GM, Silverman SG. The incidental renal mass. Radiol Clin North Am.
2011;49(2):369–383.
2. Jonisch AI, Rubinowitz AN, Mutalik PG, Israel GM. Can high-attenuation
renal cysts be differentiated from renal cell carcinoma at unenhanced CT?
Radiology. 2007;243(2):445–450.
3. Silverman SG, Mortele KJ, Tuncali K, Jinzaki M, Cibas ES. Hyperattenuating
renal masses: etiologies, pathogenesis, and imaging evaluation. Radiographics.
2007;27(4):1131–1143.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 87–89.Case 10
FIGURE 10-1FIGURE 10-2
History
Premenopausal women are evaluated for pelvic pain.
1. Which of the following are the uterine phases of the menstrual cycle? (Choose
all that apply.)
A. Menstruation phase
B. Proliferative phase
C. Follicular phase
D. Secretory phase
2. In which phase of the menstrual cycle is the endometrial complex the thickest,
as shown in Figure 10-1?
A. Menstruation phase
B. Proliferative phase
C. Follicular phase
D. Secretory phase
3. What is the thin T2 low signal band between the endometrium and the outer
myometrium visualized on magnetic resonance imaging (MRI), as shown in
Figure 10-2?
A. Central zone
B. Junctional zone
C. Proliferative zone
D. Fibromuscular stroma
4. The arterial supply to the uterus originates from which vessel?A. Uterine artery arising from the external iliac artery
B. Uterine artery arising from the internal iliac artery
C. Arcuate artery arising from the pudendal artery
D. Arcuate artery arising from the ovarian artery
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 10
Normal Uterus Anatomy
1. A, B, and D. Each menstrual cycle, on average lasting 28 days, can be divided
into three phases related to events in the ovary (ovarian cycle based on
changes in the follicles) and in the uterus (uterine cycle based on the changes
in the endometrium). Menstruation is the initial phase of the uterine cycle
(days 1 to 4). The proliferative phase is the second preovulatory phase of the
uterine cycle (days 5 to 14), when estrogen causes the mucous layer of the
uterus (endometrium) to grow (proliferate). These two uterine phases overlap
the follicular ovarian phase. After ovulation, the secretory phase is the third
phase of the uterine cycle (days 15 to 28), and it corresponds to the luteal
phase of the ovarian cycle.
2. D. During the secretory phase, under the influence of progesterone produced
by the corpus luteum, the endometrium thickens to prepare for potential
implantation of an embryo. If implantation does not occur, the corpus luteum
will involute, causing sharp drops in levels of both progesterone and
estrogen. The hormone drop causes the endometrium to shed during
menstruation.
3. B. The junctional zone is the inner myometrium composed of densely
arranged smooth muscle fibers. These smooth muscle fibers are visualized on
MRI T2 images as a low-signal interface separating the endometrium of
highsignal intensity from the outer myometrium. The outer myometrium has a
less compact smooth muscle arrangement and increased intercellular matrix
and vascularity and therefore shows higher T2 signal intensity than the
junctional zone, as seen in Figure S10-2.
4. B. The arterial supply to the uterus comes from the uterine artery, a branch of
the anterior trunk of the internal iliac artery.
Comment
Anatomy of the Uterus
The uterus is a muscular organ with a triple-layered wall consisting of a mucous
membrane that lines the uterine cavity (endometrium composed of a single layer
of columnar epithelium), a middle myometrium (smooth muscle), and outer serosa
(perimetrium) (Figures S 10-1 and S10-2). The uterus is divided into the cervix and
corpus, with the fundus and cornua being part of the corpus uteri. The fallopian
tubes insert at the cornua. The arterial supply to the uterus comes from the uterine
artery, a branch of the anterior trunk of the internal iliac artery. The uterine
arteries anastomose with each other through arcuate arteries and reach the hilum
of the ovary to join the ipsilateral ovarian artery.
Imaging Findings
On ultrasonography, the normal endometrial complex varies with the menstrual
cycle and should be measured in the sagiNal plane (Figure S10-1). I n the early
proliferative phase, the endometrium appears as a single echogenic line. Later in
the proliferative phase, three longitudinal lines can be seen (Figure S10-3). A fter
ovulation, the secretory endometrium appears as a thick echogenic complex
(Figure S10-1). I n premenopausal women, the endometrial stripe thickness, when
measured on sagiNal image outer-to-outer margin in a proliferative phase, is up to
11 mm, and in a secretory phase it is up to 16 mm. I n postmenopausal women, themean endometrial stripe thickness is 4 to 8 mm; on hormonal replacement therapy
it may increase up to 12 mm.
On MRI , the uterine anatomy is best defined on T2-weighted images where the
endometrial complex shows T2 hyperintense signal (Figure S10-4) secondary to
mucinous rich endometrial glands and stroma. The junctional zone, inner
myometrium, is an interface observed on MRI as a low-signal band on T2 images
that separates the endometrium of high-signal intensity from the outer
myometrium with intermediate high signal (Figure S10-2). The normal thickness of
the junctional zone is about 8 mm. Thickness above the threshold of 12 mm is a
strong criterion for the diagnosis of adenomyosis (Figure S10-4). The junctional
zone measurement should be made on a midsagiNal image of the long axis of the
uterus. The uterine cervix has the following distinct zones on T2-weighted images
(F igure S10-5): central hyperintense mucous layer and high-signal intensity
endocervical mucosa and glands with numerous folds and clefts (combined
thickness is 2 to 3 mm), hypointense fibrous stroma (3 to 8 mm), and outer
intermediate signal intensity loose stroma. I n some women, a pseudoseptum can
be seen in the cervix on T2-weighted imaging (Figure S10-6), which is thought to
represent the endocervical folds that can mimic a cervical septum.
The uterine zonal anatomy is best visualized during the reproductive years and
may not be well seen in prepubertal and postmenopausal women.
References
1. El Jack AK, Siegelman ES. “Pseudoseptum” of the uterine cervix on MRI. J
Magn Reson Imaging. 2007;26(4):963–965.
2. Nalaboff KM, Pellerito JS, Ben-Levi E. Imaging the endometrium: disease and
normal variants. Radiographics. 2001;21(6):1409–1424.
3. Novellas S, Chassang M, Delotte J, et al. MRI characteristics of the uterine
junctional zone: from normal to the diagnosis of adenomyosis. AJR Am J
Roentgenol. 2011;196(5):1206–1213.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 257–258.Case 11
FIGURE 11-1FIGURE 11-2
History
A 39-year-old woman, para 3, has an adnexal mass found during ultrasonography
assessment of placement of an intrauterine device.
1. Which of the following would be included in the differential diagnosis for the
imaging findings presented? (Choose all that apply.)
A. Benign cyst
B. Borderline ovarian serous tumor
C. Ovarian carcinoma
D. Endometrioma
2. What feature of borderline ovarian tumors can distinguish them from other
epithelial ovarian neoplasms?
A. Bilaterality
B. Association with breast cancer (BRCA mutations)
C. Symptomatic presentation with pleural effusion
D. There is no specific differentiating feature
3. Which is TRUE regarding women with borderline ovarian tumors compared
with women with invasive ovarian cancers?
A. They are typically older.
B. They have poor prognosis.
C. They are more likely to have early stage disease.
D. They typically present with pelvic pain at time of diagnosis.
4. Does the ultrasonography appearance of borderline ovarian tumors allow foraccurate preoperative diagnosis?
A. Yes, because septations are a diagnostic feature.
B. Yes, because papillary nodules are a diagnostic feature.
C. No, because hemorrhage obscures internal complexity.
D. No, because there is overlap between imaging features.
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 11
Borderline Ovarian Serous Tumor
1. B and C. Borderline ovarian serous tumor and ovarian carcinoma should be
considered in the differential for a complex cystic multilocular adnexal mass
with septations and solid components. A benign simple cyst should be
unilocular and contain simple fluid. Endometrioma on ultrasonography
typically shows low-level echoes from hemorrhage and should not contain
solid elements other than nonvascular retracted clots.
2. D. There are no specific features that differentiate borderline ovarian tumors
from other epithelial ovarian neoplasms.
3. C. Patients with borderline ovarian tumors are typically younger and report
incidentally found adnexal masses on routine gynecologic examination. They
are more likely to have early stage disease and have a relatively excellent
prognosis.
4. D. If the correct diagnosis of borderline ovarian tumor is made preoperatively,
a conservative fertility-sparing laparoscopic surgery can be performed.
However, there are many overlapping sonographic features between the
benign cystic lesions, borderline ovarian tumors, and invasive ovarian
carcinomas (stage I ovarian cancers). Benign lesions may rarely contain
papillae and septa. Up to 17% of borderline ovarian tumors appear as
unilocular smooth anechoic cysts without endophytic papillary growth.
Papillary projections are present in 13% of benign neoplasms, 67% of
borderline ovarian tumors, and 38% of malignant neoplasms.
Comment
Etiology
Borderline tumors are also known as ovarian tumors of low malignant potential
and represent approximately 10% to 20% of all ovarian malignancies. The majority
of borderline tumors show serous histology. Serous borderline tumors are typically
stage I at diagnosis (approximately 75% of the time) and 25% to 50% are bilateral.
The other common cellular type is mucinous, which is stage I 90% of the time at
diagnosis and is bilateral less than 10% of the time. Endometrioid, clear cell, and
transitional cell (Brenner) borderline tumors are rare. They are usually unilateral
and confined to the ovary. A s a whole, borderline tumors are characterized by the
absence of stromal invasion, although microinvasion has been documented in up
to 10% of cases.
Clinical Presentation
Women diagnosed with borderline tumors are on average 10 years younger than
women with invasive ovarian cancers; up to 45% of these patients are younger than
40 years at presentation. Patients with borderline tumors are more likely to have
early stage disease than those with invasive cancers, and they typically have a
relatively excellent prognosis. The 5-year survival rate for women with stage I
borderline tumors is approximately 95% to 97%. Borderline tumors are rarely seen
in women with BRCA mutations. Most patients with a borderline tumor have an
asymptomatic adnexal mass noted either on bimanual examination or as an
incidental finding on pelvic sonography. I f the patient is experiencing symptoms,
they are usually typical of an adnexal mass, such as dyspareunia or pelvic pain.
Imaging FindingsBorderline tumors are difficult to correctly preoperatively diagnose with imaging
methods, such as sonography or magnetic resonance imaging, because the
imaging features may overlap with invasive and benign ovarian tumors. Borderline
tumors may present as unilocular or multilocular, partially solid tumors (Figures
S11-1, S11-2, S11-3, and S11-4) with irregular and endophytic papillary projections.
A dditionally, it is difficult to identify the histologic type of borderline ovarian
tumor by imaging. S erous borderline ovarian tumors are smaller than mucinous
types; they are multilocular in 30% of cases and present with solid parts or
papillary paNern in the majority of cases (78%). Mucinous borderline ovarian
tumors are multilocular in 50% of cases and present with solid parts or papillary
paNern in only 40% of cases. One of the roles for imaging in evaluation of
borderline tumors is surveillance for recurrence in patients who have undergone
conservative, fertility-sparing surgical treatment, which is common in this younger
patient population.
References
1. Fischerova D, Zikan M, Dundr P, Cibula D. Diagnosis, treatment, and
followup of borderline ovarian tumors. Oncologist. 2012;17(12):1515–1533.
2. Morotti M, Menada MV, Gillott DJ, Venturini PL, Ferrero S. The preoperative
diagnosis of borderline ovarian tumors: a review of current literature. Arch
Gynecol Obstet. 2012;285(4):1103–1112.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 292–297.Case 12
FIGURE 12-1FIGURE 12-2
History
A 62-year-old woman has right lower quadrant discomfort; family history of
ovarian cancer, elevated carcinoma antigen 125 (CA-125).
1. Which of the following would be included in the differential diagnosis for the
imaging findings presented? (Choose all that apply.)
A. Endometrioma
B. Tuboovarian abscess
C. Epithelial ovarian tumor
D. Ovarian metastasis
2. Which imaging features are suggestive of malignant epithelial tumor?
A. Diameter less than 4 cm
B. Unilocular cystic mass
C. Wall thickness or septations less than 3 mm
D. Ascites, peritoneal implants, or adenopathy
3. Which of the following features is more characteristic of mucinous than of
serous ovarian tumor?
A. Pseudomyxoma peritonei
B. Unilocular structure
C. Papillary projections
D. Psammomatous calcifications
4. Which of the following statements is TRUE regarding clear cell carcinoma?
A. May develop in patients with endometriosisB. More frequent than serous type
C. Typically present at late stage
D. Better prognosis at an advanced stage than the advanced stages of other
ovarian cancers
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 12
Serous Ovarian Carcinoma
1. C and D. A complex cystic and solid extrauterine mass in the pelvis may
represent a primary ovarian malignancy (epithelial type is the most common
65%) or ovarian metastasis (5% of ovarian neoplasms are caused by metastasis
from primary cancer of the gastrointestinal tract, breast, lymphatics, or pelvic
viscera). Endometriomas show hemorrhage and lack enhancing solid tissue,
although they may have solid-appearing debris or clots without enhancement
or vascular flow on color Doppler imaging. Tuboovarian abscess typically
does not contain internal vascular solid tissue but may show peripheral wall
enhancement.
2. D. Serous tumors are the most common type of epithelial ovarian neoplasms,
and the majority are cystadenomas, which can be benign (60%) or borderline
malignancy (15%); often they are unilocular and large. Malignant
cystadenocarcinomas constitute 25% of serous neoplasms. Signs of carcinoma
include size over 4 cm, solid mass, multilocular with thick nodular walls or
septations above 3 mm, papillary fronds, contrast enhancement, presence of
ascites, peritoneal implants, or adenopathy.
3. A. Mucinous tumors are slightly less common than serous type, and 95% of
them are benign or of borderline malignancy. Rarely, malignant mucinous
cystadenocarcinoma may rupture and lead to pseudomyxoma peritonei with
gelatinous implants on peritoneal surfaces causing mass effects. Serous
cystadenomas are typically unilocular, whereas serous cystadenocarcinomas
appear as multilocular cystic ovarian tumors with papillary projections;
psammomatous bodies may be present during histologic examination.
4. A. Clear cell carcinomas have an incidence of less than 5% of all ovarian
malignancies. An association between clear cell carcinomas and
endometriosis has been established and is reported in 25% to 58% of cases.
When compared with their serous counterparts, a greater proportion of clear
cell carcinomas present as early stage (I-II) tumors. They are often associated
with a large pelvic cystic mass, which may account for their earlier diagnosis,
and rarely occur bilaterally. However, they have a poorer prognosis in
advanced stages when compared with other epithelial ovarian carcinomas
with overall poor response to chemotherapy.
Comment
Epidemiology
Ovarian cancer is the second most common gynecologic malignancy, the most
common cause of gynecologic cancer death, and the fifth leading cause of cancer
death in women in the United S tates. Ovarian neoplasms can be subdivided into
four categories: epithelial, germ cell, sex cord-stromal, and metastatic. Epithelial
tumors are most common, representing 60% of all ovarian neoplasms and 85% of
malignant ovarian neoplasms. Epithelial neoplasms are further classified into
subtypes based on epithelial differentiation: serous (high and low grade),
mucinous, endometrioid, clear cell, and transitional cell (Brenner). High-grade
serous carcinoma (Figures S 12-1, S12-2, S12-3, and S12-4) is the most common
histologic subtype. The incidence of epithelial tumors increases with age, peaking
in the seventh decade; the average age at diagnosis in the United S tates is 63. Theage at diagnosis is younger among women with a hereditary ovarian cancer
syndrome, for example, breast cancer susceptibility genes (BRCA1 or BRCA2) and
Lynch syndrome.
Pathogenesis
A lthough the pathogenesis of epithelial ovarian cancer is not fully understood,
ovulation is considered an important factor. Ovulation is thought to cause
repeated minor trauma and cellular repair of the surface epithelium, predisposing
it to neoplasia. The fact that nulliparity, early menarche, and late menopause are
all risk factors for epithelial ovarian cancer and that multiparity, late menarche,
early menopause, lactation, and use of oral contraceptives (i.e., fewer ovulation
cycles) are associated with reduced risk helps to support this theory.
A lternatively, emerging evidence suggests that ovarian tumors may actually
originate in other pelvic organs and involve the ovary secondarily. I t has been
proposed that serous tumors arise from the implantation of epithelium from the
fallopian tube or peritoneum. Endometrioid and clear cell tumors are associated
with endometriosis, and endometrium implants are thought to be their source.
The origin of mucinous tumors is not well characterized; but, together with
transitional cell (Brenner) tumors, they are thought to originate from
transitionaltype epithelial nests at the tubal-mesothelial junction by a process of metaplasia.
There are marked differences between the low-grade and high-grade serous
tumors. Low-grade tumors are indolent, present in stage I (tumor confined to the
ovary), and develop from well-established precursors (atypical proliferative
borderline tumors, which are characterized by specific mutations). I n contrast,
high-grade serous tumors are aggressive, present in the advanced stage, and
develop from intraepithelial carcinomas in the fallopian tube.
References
1. Kurman RJ. Origin and molecular pathogenesis of ovarian high-grade serous
carcinoma. Ann Oncol. 2013;24(Suppl 10):x16–x21.
2. Kurman RJ, Shih I-M. The origin and pathogenesis of epithelial ovarian cancer
—a proposed unifying theory. Am J Surg Pathol. 2010;34(3):433–443.
3. Lim D, Oliva E. Precursors and pathogenesis of ovarian carcinoma. Pathology.
2013;45(3):229–242.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 287–292.Case 13
FIGURE 13-1FIGURE 13-2
History
A 43-year-old nulligravida woman has recurrent abdominal pain.
1. The T1 hyperintense adnexal masses and the uterine disease shown in Figures
13-1 and 13-2 represent these entities (choose all that apply):
A. Adnexal abscess
B. Endometritis
C. Adenomyosis
D. Endometriosis
2. What is the junctional zone on magnetic resonance (MR) imaging?
A. An interface on T1-weighted images between the inner and outer
myometrium
B. A high-signal layer on T2-weighted images between endometrium and
myometrium
C. An interface on T2-weighted images between the outer myometrium and
serosa
D. A low-signal layer on T2-weighted images between endometrium and
myometrium
3. The threshold for thickening of the junctional zone as a strong indicator of
adenomyosis is at:
A. 5 mm
B. 8 mm
C. 12 mmD. 25 mm
4. What is the association between endometriosis and adenomyosis?
A. Increased incidence of adenomyosis among infertile women with
endometriosis
B. Less than 1% of women with endometriosis have concomitant
adenomyosis
C. Endometriosis and adenomyosis are not related
D. All women with endometriosis also have concomitant adenomyosis
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 13
Endometriosis and Adenomyosis
1. C and D. The T2-weighted image (Figure S13-2) shows hyperintense foci in the
region of inner myometrium, with intervening dark signal, as seen in
adenomyosis. T1-weighted image (Figure 13-1) shows hyperintense signal in
bilateral adnexal regions, compatible with hemorrhage, as seen in
endometriomas. Hemorrhage is unlikely in an abscess, and infected debris is
usually isointense and not as intensely bright in T1 signal. Endometritis refers
to inflammation of the endometrium, which in this case appears normal.
2. D. The junctional zone is a distinct layer of low signal on T2-weighted images,
separating the high-signal endometrium from the intermediate-signal outer
myometrium. Histologically, this zone corresponds to the innermost layer of
the myometrium.
3. C. The threshold for junctional zone thickness to diagnose adenomyosis is
12 mm.
4. A. The prevalence of adenomyosis has been reported to range from 8.8% to
31%. Around 27% to 40% of women with endometriosis have concomitant
adenomyosis. The incidence of adenomyosis among infertile women with
endometriosis is up to 70%.
Comment
Pathophysiology
Endometriosis is a disease in which endometrial tissue implants outside the
uterus. S ome 27% to 40% of women with endometriosis have concomitant
endometrial implants at the interface of the endometrium and myometrium, which
is a condition called adenomyosis. I nvolvement of the myometrium can include
the entire interface, termed “diffuse adenomyosis,” or it can be focal, “focal
adenomyosis.” When adenomyosis has a masslike appearance, it is called an
adenomyoma.
Junctional Zone
The term junctional zone describes the interface between the endometrium and
myometrium observed on T2-weighted MR images. A distinct low-signal layer of
the junctional zone separates the high-signal intensity endometrium from the
intermediate-signal outer myometrium. Histologically, this zone corresponds to
the innermost layer of the myometrium. J unctional zone myocytes have different
morphologic characteristics from those of the typical myocytes of the outer
myometrium, such as a greater relative nuclear area, a looser extracellular matrix,
and lower water content. The inner myometrium has a unique concentric
arrangement of smooth-muscle fibers in contrast to the longitudinal orientation of
the smooth-muscle fibers of the outer myometrium. The thickness of the
junctional zone is crucial to the diagnosis of adenomyosis; a 12-mm threshold is a
strong criterion for this diagnosis. The presence of ectopic endometrial tissue and
stroma in the myometrium induces a hypertrophic reaction of smooth-muscle cells
surrounding the ectopic glands within the junctional zone leading to its
enlargement.
Key Imaging Features
Ectopic endometrial tissue can be implanted on the ovaries leading to
development of endometriomas (Figures S13-1 and S13-3), which contain T1 brighthemorrhagic content with no change with fat suppression. Ectopic endometrial
tissue within the junctional zone leads to adenomyosis with a thickened irregular
junctional zone of low intensity on T2-weighted images and T2 bright microcystic
implants (Figure S13-2).
Link Between Adenomyosis and Endometriosis
A common pathogenesis for adenomyosis and endometriosis has been
hypothesized. A 43% prevalence of adenomyosis in patients with endometriosis
has been reported in patients with severe or incapacitating dysmenorrhea and
deep dyspareunia and in patients with endometriosis of the rectosigmoid. A mong
infertile women with endometriosis, up to 70% also have adenomyosis.
References
1. Benagiano G, Habiba M, Brosens I. The pathophysiology of uterine
adenomyosis: an update. Fertil Steril. 2012;98(3):572–579.
2. Novellas S, Chassang M, Delotte J, et al. MRI characteristics of the uterine
junctional zone: from normal to the diagnosis of adenomyosis. AJR Am J
Roentgenol. 2011;196(5):1206–1213.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 267–270.Case 14
FIGURE 14-1FIGURE 14-2
History
A 37-year-old man has dysuria.
1. What are the anatomic regions of the prostate that are visualized on magnetic
resonance imaging, as illustrated on T2-weighted images in Figures 14-1 and
14-2? (Choose all that apply.)
A. Peripheral zone (PZ)
B. Transition zone (TZ)
C. Central zone (CZ)
D. Anterior fibromuscular stroma (AFS)
2. Benign prostate hypertrophy arises from which anatomic zone of the prostate?
A. PZ
B. TZ
C. CZ
D. AFS
3. The ejaculatory ducts are formed from?
A. Ducts draining periurethral Skene glands
B. Union of seminal vesicles and vas deferens
C. Ducts draining Cowper glands
D. Union of Müllerian and Wolffian ducts
4. The majority of prostate adenocarcinomas arise from?
A. PZ
B. TZC. CZ
D. AFS
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 14
Anatomy of the Prostate
1. A, B, C, and D. The PZ envelops the posterior, lateral, and apical portions of
the prostate. The PZ is mesodermal in origin and contains the majority (75%)
of prostatic glandular tissue. On T2W images, a normal PZ has a
homogeneously bright signal. The TZ surrounds the prostatic urethra and is
endodermal in origin. In young men, the TZ accounts for only 5% to 10% of
prostatic glandular tissue. On T2W images, the TZ has variable signal
characteristics. The CZ is located immediately around the ejaculatory ducts in
the superior posterior prostate and contains more stroma than glandular
tissue. On T2W images, the CZ has a homogeneously low signal. The AFS is a
thin layer of fibromuscular tissue that contains no glandular tissue. On T2W
images the AFS has a dark signal.
2. B. BPH arises in the TZ of the prostate.
3. B. Ejaculatory ducts are formed by the union of the seminal vesicles and vas
deferens and drain to each side of the prostatic utricle. Ejaculatory ducts are
derivatives of the mesonephric ducts (Wolffian ducts). Skene glands (female
prostate) are glands located on the anterior wall of the vagina. Cowper
(bulbourethral) glands are located posterior and lateral to the membranous
portion of the urethra at the base of the penis.
4. A. The PZ is the site of origin of most prostatic adenocarcinomas; about 70%
of adenocarcinomas arise in the PZ.
Comment
Anatomy
A natomically, the prostate is divided from superior to inferior into the base (just
below the urinary bladder), the midgland (the mid one third), and the apex distally
(Figure S14-1). The prostate gland is composed of glandular tissue (PZ, CZ, and
TZ) and anterior nonglandular tissue (fibromuscular stroma).
The ducts of the PZ and those of the smaller CZ account for 95% of the glandular
tissue of the prostate. The PZ envelops the posterior, lateral, and apical portions of
the prostate (Figures S 14-1, S14-2, and S14-3). I t makes up most of the apex of the
prostate. The PZ is the major glandular component of the prostate, comprising
70% of the prostate in healthy young men. A bout 70% of adenocarcinomas arise in
the PZ.
The CZ is located posteriorly and superiorly between the PZ and the proximal
urethra (Figures S 14-1 and S14-2). I t contains more stroma than glandular tissue
and is located immediately around the ejaculatory ducts. A bout 10% of prostate
cancers arise in the CZ.
The third glandular area is the TZ, which surrounds the proximal prostatic
urethra (that portion of the urethra cephalad to the verumontanum) and accounts
for not more than 5% to 10% of the normal glandular prostate in young men
(F igure S14-3). This zone, which is small and inconsequential in young men,
becomes hyperplastic and progressively larger with age due to benign prostatic
hyperplasia. About 20% of prostate cancer arises in the TZ.
The term central gland refers to the CZ and the TZ combined.
The fibromuscular stroma is located anteriorly (Figure S14-3) and contains
smooth muscle, which mixes with periurethral muscle fibers at the bladder neck.The seminal vesicles and vas deferens (Figure S14-4) both are derivatives of
mesonephric ducts (also known as Wolffian ducts) and are located just above the
base of the prostate and behind the urinary bladder. The ducts of the seminal
vesicles join the vas deferens to form the ejaculatory ducts (Figure S14-2), which
open into the mid prostatic urethra at the level of the verumontanum.
The normal prostate measures approximately 4 cm in length (cephalocaudal),
4 cm in transverse diameter, and 3 cm in anteroposterior. The normal volume
ranges from 20 to 25 mL, and the normal weight is approximately 20 g. The
prostate is conventionally divided into sextants based on division of the gland into
thirds in the craniocaudal direction (base, mid, apex) and into the right and left
sides.
References
1. Ayala AG, Ro JY, Babaian R, Troncoso P, Grignon DJ. The prostatic capsule:
Does it exist? Its importance in the staging and treatment of prostatic
carcinoma. Am J Surg Pathol. 1989;13(1):21–27.
2. Claus FG, Hricak H, Hattery RR. Pretreatment evaluation of prostate cancer:
role of MR imaging and 1H MR spectroscopy. Radiographics. 2004;24(Suppl
1):S167–S180.
3. Ryu J, Kim B. MR imaging of the male and female urethra. Radiographics.
2001;21(5):1169–1185.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 315.Case 15
FIGURE 15-1
FIGURE 15-2
History
A 65-year-old man has elevated prostate-specific antigen (PSA) at 8.2 ng/mL.
1. Which of the following would be included in the differential diagnosis for the
imaging findings presented on the transrectal ultrasonography? (Choose all
that apply.)
A. Focal bacterial prostatitis
B. Granulomatous prostatitis
C. Prostatic intraepithelial neoplasia (PIN)D. Prostate cancer
2. What is the most frequently diagnosed cancer in men?
A. Lung cancer
B. Prostate cancer
C. Colon cancer
D. Pancreatic cancer
3. What is the threshold for PSA value to be considered abnormal (in ng/mL)?
A. 0.5
B. 1
C. 2
D. 4
4. What is the first line imaging modality used for diagnosis of prostate cancer?
A. Ultrasonography
B. Computed tomography
C. MRI
D. Bone scintigraphy
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 15
Prostate Carcinoma
1. A, B, C, and D. The most common diseases of the prostate gland include
prostatitis, benign prostatic hyperplasia (BPH), and prostate cancer.
Prostatitis is often a clinical diagnosis, caused either by bacterial or
nonbacterial acute or chronic inflammation. Prostatitis often leads to elevated
PSA. Elevation in PSA is also a feature of prostate cancer. High-grade PIN is
considered the most likely precursor of prostatic carcinoma because
carcinoma will develop in most patients with PIN within 10 years. Both
benign and malignant conditions of the prostate may result in focal or diffuse
abnormalities seen on imaging. Prostate cancer and PIN tend to present as a
focal nodule. whereas prostatitis typically results in diffuse changes of the
gland.
2. B. Prostate cancer is the most frequently diagnosed cancer in men, accounting
for 25% of all cancers in men, compared with 15% for lung cancer.
3. D. PSA levels above the threshold of 4 ng/mL are considered abnormal.
However, elevation in PSA above this threshold has low specificity for
prostate cancer detection. In 70% to 80% of patients with mild elevation of
PSA, the increased PSA level is in fact caused by benign conditions such as
BPH or prostatitis, leading to a false-positive result.
4. A. Ultrasonography is widely used for men with elevated PSA and/or
abnormal digital rectal examination (DRE) in the form of transrectal
ultrasonography (TRUS), with the primary intent to assess the volume of the
prostate gland and for visual guidance for prostate biopsy. Computed
tomography and bone scintigraphy are typically used for evaluation of
highrisk prostate cancer to detect metastatic disease. MRI is used for cancer
detection in men with negative TRUS biopsy and persistently elevated PSA, in
men with low grade/low volume prostate cancer managed by active
surveillance, and for staging.
Comment
Prevalence
Prostate cancer is the second leading cause of cancer-related death in men,
accounting for 9% of cancer deaths, which is a value exceeded only by the death
rate from lung cancer in men (30%). S ixteen percent of men (one in six) will have
prostate cancer during their lifetime. The prevalence of prostate cancer increases
with age; 34% of men in the fifth decade of life and up to 70% of men aged 80 years
or older have histologic evidence of prostate cancer. Most patients in whom
prostate cancer is diagnosed die with the disease rather than of the disease.
Diagnosis and Management
Currently, prostate cancer screening is based on assessment of the level of PS A
and results of D RE. Both markers have suboptimal accuracy for the diagnosis of
prostate cancer. D RE is affected by interexaminer variability and is limited to
assessment of peripheral zone tumors. PS A screening has been criticized because
of its relatively poor sensitivity and specificity. Elevation of PS A above the
threshold of 4 ng/mL (clinically commonly regarded as abnormal) has low
specificity for prostate cancer. I n 70% to 80% of patients with mild elevation of
PS A level, the increased PS A level is in fact caused by benign conditions, resultingin a false-positive PS A finding and subsequently in an unnecessary prostate
biopsy. At least 15% and up to 44% of biopsy-proved prostate cancers occur in
patients with PSA levels in the accepted normal range below 4 ng/mL.
TRUS was found to have only a 15.2% positive predictive value in the detection
of cancers, compared with 28% for D RE. Therefore, both techniques suffer from
the inability to differentiate benign processes mimicking prostate cancer from true
positive cases. Prostate biopsy has been found to miss cancer in 10% to 38% of men
eventually found to have prostate cancer, and, typically, patients require repeat
biopsies until a diagnosis is made. MRI continues to evolve as a powerful modality
for detection and localization of prostate cancer. I t is currently being used as a
problem-solving tool for inconclusive TRUS biopsy, for the monitoring of small
volume prostate cancer in active surveillance programs, and for staging of prostate
cancer.
Imaging Findings
Most prostate cancers are hypoechoic (Figures S 15-1 and S15-2) to the normal
peripheral zone on TRUS (60% to 70%); up to 40% of lesions are not distinguished
from the background normal parenchyma because of being isoechoic or even
hyperechoic. On MRI , prostate cancer shows a focal T2 hypointense lesion (Figure
S15-3) associated with focal abnormal enhancement (Figure S15-4).
References
1. Bonekamp D, Jacobs MA, El-Khouli R, Stoianovici D, Macura KJ.
Advancements in MR imaging of the prostate: from diagnosis to
interventions. Radiographics. 2011;31(3):677–703.
2. Patel AR, Jones JS, Rabets J, DeOreo G, Zippe CD. Parasagittal biopsies add
minimal information in repeat saturation prostate biopsy. Urology.
2004;63(1):87–89.
3. Spajic B, Eupic H, Tomas D, Stimac G, Kruslin B, Kraus O. The incidence of
hyperechoic prostate cancer in transrectal ultrasound-guided biopsy
specimens. Urology. 2007;70(4):734–737.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 329–332.Case 16
FIGURE 16-1FIGURE 16-2
History
A n 11-year-old girl with 10 months of intermiNent lower abdominal pain has
difficulty in voiding and has incomplete bladder emptying. The patient has not
started her periods and denies vaginal bleeding or discharge.
1. Which pathologic entities could explain imaging findings in Figures 16-1 and
16-2 (Choose all that apply)?
A. Vaginal agenesis
B. Vaginal septum
C. Imperforate hymen
D. Labial adhesions
2. What does hematocolpometra mean?
A. Accumulation of blood in the vaginal cyst
B. Accumulation of blood in the vagina and uterus
C. Accumulation of blood in the vagina
D. Accumulation of blood in the endometrial cavity and fallopian tubes
3. Is imperforate hymen associated with other congenital anomalies?A. No association
B. Yes, with renal agenesis
C. Yes, with bladder exstrophy
D. Yes, with urethral diverticulum
4. What is the standard treatment of imperforate hymen?
A. Ablation
B. Coagulation
C. Surgery
D. Embolization
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 16
Hematocolpometra with Imperforate Hymen
1. A, B, C, and D. Vaginal agenesis, vaginal septum, imperforate hymen, and
acquired labial adhesions may all lead to outflow obstruction and retention of
secretions and menstrual blood in the vagina.
2. B. Hematocolpometra means accumulation of menstrual blood in the vagina
(colpos) and uterus (metra) due to outflow obstruction, typically with
imperforate hymen. Retrograde menstruation can cause dilatation of fallopian
tubes.
3. A. Imperforate hymen is typically not associated with other congenital
anomalies; extensive investigation for other malformations is often
unnecessary. Urethral diverticulum is usually an acquired condition.
4. C. The standard treatment for imperforate hymen is surgical hymenectomy.
Comment
Etiology
I mperforate hymen is an uncommon anomaly of the reproductive tract that occurs
when a normal lumen in the hymen fails to develop. Even though it is a congenital
disorder present at birth, it often remains undetected until puberty. In adolescence
the obstructed outflow leads to accumulation of menstrual blood in the vagina, in
the uterus, and in the fallopian tubes, with consequent distention of these
structures. Patients usually have lower abdominal pain, pelvic mass, primary
amenorrhea, and urinary symptoms. D iagnosis can be suspected by history and
physical examination and confirmed with imaging.
Differential Diagnosis
Other anatomic anomalies that should be considered in the differential diagnosis
include vaginal septum (transverse or longitudinal), vaginal agenesis, vaginal cyst,
and acquired labial adhesions.
Key Imaging Findings
Pelvic ultrasonography demonstrates a markedly distended vagina and
endometrial cavity by fluid with low-level homogeneous internal echogenicity
(Figure S16-1). A lthough ultrasonography is usually sufficient for assessment of
most cases, magnetic resonance imaging (MRI ) can be performed for anatomic
evaluation with a larger field of view. MRI typically shows distension of the vagina
(hematocolpos), uterine cavity (hematometra), and possibly fallopian tubes with
fluid that has characteristics of blood products, such as bright signal on
T1weighted images (Figure S16-2) and dark “shading” signal on T2-weighted images
(Figure S16-3).
Management
Hematocolpometra secondary to an imperforate hymen and retrograde
menstruation should be considered in the differential diagnosis of abdominal or
back pain in premenarchal adolescent girls. The standard treatment for
imperforate hymen is surgical hymenectomy. Because imperforate hymen is not
typically associated with other congenital anomalies, extensive investigation for
others malformations is often unnecessary. Most women have normal fertility and
excellent long-term prognosis.References
1. Basaran M, Usal D, Aydemir C. Hymen sparing surgery for imperforate
hymen: case reports and review of literature. J Pediatr Adolesc Gynecol.
2009;22:e61–e64.
2. Sailer JF. Hematometra and hematocolpos: ultrasound findings. AJR Am J
Roentgenol. 1979;132:1010–1011.
3. Stone SM, Alexander JL. Images in clinical medicine Imperforate hymen with
hematocolpometra. N Engl J Med. 2004;351:e6.Case 17
FIGURE 17-1FIGURE 17-2
History
Two premenopausal patients had an enlarged uterus during physical examination.
1. What are the anatomic locations of fibroids visualized in Figures 17-1 and 17-2
(Choose all that apply)?
A. Subcapsular
B. Submucosal
C. Subserosal
D. Intramural
2. What are the most common magnetic resonance imaging (MRI) features of
leiomyoma?
A. T1 hyperintense with well-defined margins
B. T2 hypointense with poorly defined margins
C. T1 hyperintense with poorly defined margins
D. T2 hypointense with well-defined margins
3. Which leiomyomas are most commonly symptomatic?
A. Subserosal
B. With hyaline degeneration
C. Submucosal
D. With fatty degeneration
4. What hormone stimulates growth of leiomyomas?
A. Estrogen
B. Progesterone
C. AndrogenD. Gonadotropin-releasing hormone
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 17
Uterine Leiomyomas (Fibroids)
1. B, C, and D. A submucosal leiomyoma protrudes into the uterine cavity and
can be classified according to the proportion of leiomyoma contained within
the uterine cavity: submucosal leiomyoma protruding ≥ 50% into the uterine
cavity and leiomyoma with submucosal component protruding
2. D. A leiomyoma is typically circumscribed with well-defined margins and T2
hypointense signal compared with the myometrium. Sometimes, T2 signal is
increased in cellular fibroids and with cystic necrosis. T1-weighted images
typically show isointense or hypointense signal compared with the
myometrium. Rarely, T1 high-signal can be seen with hemorrhagic (red)
necrosis.
3. C. Although submucosal leiomyomas are the least common (5% of uterine
leiomyomas), they are most commonly symptomatic and are associated with
dysmenorrhea, menorrhagia, and infertility. Subserosal leiomyomas are
usually asymptomatic; however, pedunculated subserosal leiomyomas may
undergo torsion, which results in infarction accompanied by pain. Hyaline
degeneration is the most common type of fibroid degeneration (> 60% of
cases); unless it is accompanied by rapid fibroid growth causing pressure
symptoms, it is asymptomatic. Lipoleiomyoma is typically intramural and
asymptomatic.
4. A. Leiomyomas are estrogen dependent, and there is an increased prevalence
of leiomyomas in patients with diseases associated with hyperestrogenism.
Growth of leiomyomas is stimulated mainly by estrogen. Progesterone
supplementation is used to attempt to shrink fibroids; mixed results—both
fibroid shrinkage and sometimes enlargement—have been seen. Androgen
therapy may be used to shrink fibroids. Gonadotropin-releasing hormone
agonists are used to shrink fibroids.
Comment
Clinical Background
Uterine leiomyoma is a benign smooth-muscle tumor that is detected in almost
20% of women. I ncreased prevalence and rate of growth have been reported in
A frican A merican women. These tumors are estrogen dependent, and there is an
increased prevalence of leiomyomas in patients with diseases associated with
hyperestrogenism. Rapid enlargement, degeneration, neoplastic transformation,
and growth during pregnancy are potential complications of leiomyomas.
A pproximately 10% of women who are pregnant and have uterine fibroids must be
hospitalized during the pregnancy for related complications. Hyaline, cystic,
hemorrhagic, or faNy degeneration of leiomyomas may occur. Rarely, leiomyomas
may become infected or may undergo sarcomatous transformation, which is a
complication in 0.5% of patients.
Classification
A ccording to their location, leiomyomas are classified as submucosal (projecting
into the endometrial canal), intramural (within the myometrium), or subserosal
(beneath the serosa) as shown in Figures S 17-1, S17-2, and S17-3. A lthough
submucosal leiomyomas are the least common (5% of uterine leiomyomas), they
are most commonly symptomatic and may be associated with dysmenorrhea,menorrhagia, and infertility. Rarely, submucosal leiomyomas may become
pedunculated and prolapse into the cervical canal or vagina. I ntramural
leiomyomas, which are the most common, are most often asymptomatic, although
they occasionally can be associated with menorrhagia and infertility. S ubserosal
leiomyomas are usually asymptomatic; however, pedunculated subserosal
leiomyomas may undergo torsion, which results in infarction accompanied by
pain. Lateral growth of subserosal leiomyomas may extend along the broad
ligament and simulate an ovarian mass during both clinical and imaging
examinations. Rarely, a pedunculated fibroid may become aNached to an adjacent
structure, where it may induce a new blood supply and become detached from the
uterus (parasitic leiomyoma).
Imaging Findings
N ondegenerated uterine leiomyomas are composed of whorls of uniform
smoothmuscle cells with various amounts of intervening collagen and have a typical
appearance on MRI : well-circumscribed masses of homogeneously decreased
signal intensity compared with the outer myometrium on T2-weighted images
(Figures S 17-1 and S17-2). A heterogeneous or speckled appearance on
T2weighted images, with small or large focal areas of increased signal intensity, is
consistent with hyaline and cystic degeneration. On T1-weighted images,
leiomyomas are typically isointense or hypointense to surrounding myometrium
(Figure S17-3); sometimes they become hyperintense owing to hemorrhagic (red)
necrosis.
References
1. Murase E, Siegelman ES, Outwater EK, Perez-Jaffe LA, Tureck RW. Uterine
leiomyomas: histopathologic features, MR imaging findings, differential
diagnosis, and treatment. Radiographics. 1999;19(5):1179–1197.
2. Ruuskanen AJ, Hippeläinen MI, Sipola P, Manninen HI. Association between
magnetic resonance imaging findings of uterine leiomyomas and symptoms
demanding treatment. Eur J Radiol. 2012;81(8):1957–1964.
3. Ueda H, Togashi K, Konishi I, et al. Unusual appearances of uterine
leiomyomas: MR imaging findings and their histopathologic backgrounds.
Radiographics. 1999;19(Spec No):S131–S145.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 276.Case 18
FIGURE 18-1FIGURE 18-2
History
A 61-year-old man has a history of abdominal aortic aneurysm. Computed
tomography was performed for evaluation of aortic aneurysm.
1. Which of the following would be included in the differential diagnosis for the
findings of the kidneys presented? (Choose all that apply.)
A. Unilateral renal ptosis
B. Unilateral renal agenesis
C. Crossed fused renal ectopia
D. Unilateral pelvic kidney
2. All of the following statements are correct regarding the illustrated renal
condition, EXCEPT:
A. It is the most common form of the simple renal ectopia.
B. It is associated with renal malrotation.
C. It is better protected from injury from blunt abdominal trauma than a
normally positioned kidney.
D. Most patients with this condition are asymptomatic.
3. The illustrated renal condition is at higher risk of the following complications
than a normally positioned kidney, EXCEPT:
A. Hydronephrosis
B. Renal calculus
C. Vesicoureteral reflux
D. Renal cell carcinoma4. The illustrated renal condition is associated with aberrant vascular supply.
Which of the following is the LEAST common artery that supplies the kidney
located in the pelvis?
A. Abdominal aorta at the bifurcation
B. Common iliac artery
C. Inferior mesenteric artery
D. Internal iliac artery
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 18
Pelvic Kidney
1. D. The left kidney is located within the pelvis with its blood supply arising
from the proximal left common iliac artery near the aortic bifurcation. These
findings are compatible with congenital ectopic pelvic kidney. Renal ptosis is
low lying kidney secondary to deficiency of supportive fascia but has normal
blood supply from the abdominal aorta.
2. C. Pelvic kidney is more susceptible to injury from blunt abdominal trauma
than is the normally positioned kidney.
3. D. Pelvic kidney is predisposed to ureteropelvic junction obstruction,
vesicoureteral reflux, renal calculi, and infection. However, there is no certain
increased risk for renal cell carcinoma.
4. C. Pelvic kidney is usually associated with aberrant vascular supply, often
from at or just distal to the bifurcation of the aorta. Blood supply may also
arise from the common iliac artery and internal iliac artery. It is very unusual
that a pelvic kidney is supplied by the inferior mesenteric artery.
Comment
Renal Ectopia
The kidneys develop from the ureteral bud and metanephric blastema and migrate
in a cephalad direction out of the pelvis to the L2 level between the fourth and
eighth weeks of gestation. Renal ectopia is a congenital abnormal position of the
kidney, located inferior, superior, or on the opposite side of its usual position.
Simple renal ectopia refers to kidneys aberrantly located on their ipsilateral side.
Pelvic Kidney
Pelvic kidney is the most common form of the simple renal ectopia. I t is due to
underascent of normal cephalic migration of the fetal kidney. I n pelvic kidney, the
kidney is located in the true pelvis or anterior to the sacrum (Figures S 18-1, S18-2,
and S18-3). The kidney may be located in the lower abdomen at the level of the iliac
crest and termed abdominal ectopy. D ifferent from ptotic kidney in which the
kidney drops down when the patient stands up secondary to lack of supportive
fascia, ectopic pelvic kidney is associated with a congenitally short ureter and
aberrant blood supply (Figures S 18-1, S18-2, and S18-3). Pelvic kidney is also
malrotated because of arrest of normal rotation during the course of the migration.
Clinical Presentation
Pelvic kidneys occur in approximately 1 in 1000 live births. There is a 3:2
male-tofemale predominance. Pelvic kidney is usually asymptomatic. However, pelvic
kidneys are predisposed to ureteropelvic junction obstruction, vesicoureteral
reflux, urinary tract infection, and renal calculi. Pelvic kidney is also more
susceptible to injury from blunt abdominal trauma because of its proximity to the
pelvic ring. Blood supply to the kidney often arises at or just distal to the
bifurcation of the aorta or from common iliac, and/or internal iliac arteries (Figures
S18-1, S18-2, S18-3, and S18-4).
Management
N o treatment is needed for pelvic kidney in asymptomatic patients with normal
renal function. I f there is obstruction or renal calculus, surgical or endoscopic
intervention may be required. A berrant vascular supply to pelvic kidney isclinically important for surgical planning.
References
1. Gülsün M, Balkanci F, Cekirge S, Deger A. Pelvic kidney with an unusual
blood supply: angiographic findings. Surg Radiol Anat. 2000;22(1):59–61.
2. Singer A, Simmons MZ, Maldjian PD. Spectrum of congenital renal anomalies
presenting in adulthood. Clin Imaging. 2008;32(3):183–191.
3. Yildirim I, Irkilata HC, Aydur E, Zor M, Basal S, Goktas S. Different clinical
presentations of pelvic ectopic kidneys: report of two cases and review of the
literature. Urologia. 2010;77(3):212–215.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 55–59.This page contains the following errors:
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Case 19
FIGURE 19-1FIGURE 19-2
History
A 22-year-old woman has a history of fever, severe right upper quadrant pain, nausea,
and vomiting.
1. Which of the following would be included in the differential diagnosis for the
imaging findings of the right kidney presented? (Choose all that apply.)
A. Renal infarct
B. Acute pyelonephritis
C. Renal contusion
D. Renal lymphoma
2. Striated nephrogram can be seen in the following conditions, EXCEPT:
A. Acute high-grade ureteral obstruction
B. Acute renal vein thrombosis
C. Radiation nephritis
D. Hypertension
3. Which of the following is considered the best imaging modality to evaluate acute
pyelonephritis and its complications in adults?
A. Ultrasonography
B. Contrast-enhanced computed tomography (CT)
C. Magnetic resonance imaging (MRI)
D. Technetium-99m-dimercaptosuccinic acid (Tc-99m DMSA)
4. In which of the following situations is imaging study LEAST likely indicated?
A. An elderly patient with a history of diabetes mellitus who has symptoms of
severe acute pyelonephritisB. A young adult patient who has clinical and laboratory findings compatible
with uncomplicated acute pyelonephritis
C. A young boy with the first documented urinary tract infection
D. An adult patient with recent diagnosis of acute pyelonephritis who does not
respond to appropriate antibiotic therapy within the first 72 hours
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 19
Acute Pyelonephritis
1. B, C, and D. Wedge-shaped areas of decreased perfusion and striated
nephrogram are typical CT findings of acute pyelonephritis. Renal contusion is
seen as an ill-defined area of decreased attenuation on CT and is one of the
causes of striated nephrogram and can simulate pyelonephritis. This is less likely
in this case, though, on the basis of clinical history and diffuse right renal
involvement. Renal lymphoma can present as multiple solid renal masses or
diffuse infiltrative masses. Acute pyelonephritis occasionally simulates renal
lymphoma on imaging studies. Renal infarcts typically show sharply demarcated,
wedge-shaped areas of perfusion defect and may simulate acute pyelonephritis,
although striated nephrogram is not usually seen in renal infarcts.
2. D. Hypertension is not a cause for striated nephrogram. Acute high-grade
obstruction, acute renal vein obstruction, and after radiation therapy to the
kidney are causes of striated nephrogram.
3. B. Contrast-enhanced CT is considered the best imaging modality to detect acute
pyelonephritis and its complications. Ultrasonography is less sensitive and less
specific in the diagnosis of acute pyelonephritis. MRI findings of acute
pyelonephritis are similar to CT, but MRI does not show calcifications and gas, as
well as CT. Tc-99m DMSA renal scintigraphy is almost as sensitive as CT and is
commonly used in evaluation of pediatric acute pyelonephritis. However, it is
infrequently used in adult patients because of its low specificity as focal areas of
decreased uptake may represent abscess, infarct, cyst, or tumor.
4. B. In adults, diagnosis of acute pyelonephritis is typically made on the basis of
clinical and laboratory findings, and imaging studies are usually not required in
uncomplicated cases. In children, an imaging workup is indicated with the first
documented urinary tract infection in all boys and in all girls younger than 5
years and in older girls with recurrent urinary tract infections.
Comment
Role of Imaging Studies
A cute pyelonephritis is usually caused by ascending infection of urinary tract from
the urinary bladder. Hematogenous spread of infection from another source is less
common and usually is seen in immunocompromised patients.
I n adults, diagnosis of acute pyelonephritis is typically based on clinical features,
and imaging studies are usually not required. However, imaging studies are useful
when the diagnosis of acute pyelonephritis cannot be made clinically and when
possible complications such as abscess and emphysematous infection need to be
assessed, particularly for diabetic and immunocompromised patients. I maging
studies are also useful to assess underlying anatomic abnormality, including calculus
or urinary tract obstruction, that may prevent a rapid therapeutic response or require
further management. I maging plays a much greater role in the diagnosis of acute
pyelonephritis in children than in adults because clinical and laboratory findings
cannot reliably differentiate upper tract from lower tract infection.
Imaging Findings
I n uncomplicated acute pyelonephritis, ultrasonography usually demonstrates
normal-appearing kidneys. However, ultrasonography may show focal or global areas
of decreased or occasionally increased echogenicity and obliteration of the
corticomedullary differentiation (Figure S19-6). Color and power D opplerultrasonography may show associated hypoperfusion.
Contrast-enhanced CT is considered the best imaging study to detect acute
pyelonephritis and its complications. Typical CT findings include ill-defined
wedgeshaped lesions of decreased a; enuation and striated nephrogram, which is seen as
linear bands of alternating hypoa; enuation and hypera; enuation oriented parallel to
the axes of the tubules and collecting ducts (see Figures S19-1, S19-2, S19-3, S19-4, and
S19-5). Thickening of pelvicalyceal wall, obliteration of renal sinus and perinephric
fat, and thickening of renal fascia may also be seen. A ssociated nonenhancing fluid
collections indicate development of abscesses.
Management
Treatment with antibiotics is usually effective; however, when patients do not
respond to appropriate antibiotic therapy within the first 72 hours, an abscess should
be suspected, and an imaging study may be required.
References
1. Browne RF, Zwirewich C, Torreggiani WC. Imaging of urinary tract infection in
the adult. Eur Radiol. 2004;14(Suppl 3):E168–E183.
2. Demertzis J, Menias CO. State of the art: imaging of renal infections. Emerg
Radiol. 2007;14(1):13–22.
3. Kawashima A, LeRoy AJ. Radiologic evaluation of patients with renal infections.
Infect Dis Clin North Am. 2003;17(2):433–456.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 135–138.Case 20
FIGURE 20-1FIGURE 20-2
History
A 29-year-old woman has a history of recurrent spontaneous abortions.
1. Which uterine anomalies are the result of Müllerian duct defects? (Choose all
that apply.)
A. Uterus unicornis
B. Uterus didelphys
C. Uterus bicornis
D. Uterus septate
2. Which imaging modality is the most effective in diagnosing septate uterus?
A. Computed tomography (CT)
B. Hysterosalpingography
C. Magnetic resonance imaging (MRI)
D. Two-dimensional transvaginal ultrasonography
3. In septate uterus, the fundal contour is:
A. Concave with at least 2 cm cleft
B. Concave with at least 3 cm cleft
C. Concave with an intercornual angle greater than 105 degrees
D. Normal, flat, or slightly concave with 1 cm or less indentation
4. What is the treatment for septate uterus?
A. Hysteroscopic metroplasty
B. Reconstructive transabdominal surgery
C. Reconstructive transperineal surgery
D. Transrectal septal resection
See Supplemental Figures section for additional figures and legends for this case.A n sw e rs
Case 20
Septate Uterus
1. A, B, C, and D. Müllerian duct anomalies comprise unicornuate uterus, uterus
didelphys, bicornuate uterus, and septate uterus.
2. C. MRI provides clear delineation of internal and external uterine anatomy in
multiple imaging planes and, more importantly, reliable depiction of the external
uterine contour. CT is not used for diagnostic purposes in the evaluation of
Müllerian duct anomalies. Hysterosalpingography does not allow assessment of
the uterine fundus, which is the key to differentiating septate uterus from
bicornuate uterus. Traditional two-dimensional transvaginal ultrasonography is
not as helpful as three-dimensional ultrasonography with coronal plane
reconstruction for visualizing the uterine fundus.
3. D. In septate uterus, the fundal contour is normal (convex), flat, or slightly
concave with indentation 1 cm or less. In bicornuate uterus, the fundal cleft is
deeper than 1 cm.
4. A. Hysteroscopic metroplasty is the treatment of choice for septate uterus.
Reproductive outcome has been shown to improve after resection of the septum,
with reported decreases in the spontaneous abortion rate from 88% to 5.9% after
hysteroscopic metroplasty. Reconstructive transabdominal surgery is a treatment
method used for bicornuate uterus. However, bicornuate uteri rarely necessitate
surgical intervention. The wedge resection of the medial aspect of each uterine
horn and subsequent unification of the two cavities may be considered in
selected patients with recurrent second-trimester and third-trimester pregnancy
losses.
Comment
Classification of Müllerian Duct Anomalies
The classification system of Müllerian duct anomalies was developed by the American
Fertility Society.
• Class I anomalies consist of segmental agenesis and variable degrees of
uterovaginal hypoplasia.
• Class II anomalies are unicornuate uteri that represent partial or complete
unilateral hypoplasia.
• Class III anomalies are comprise uterus didelphys, in which duplication of the
uterus results from complete nonfusion of the Müllerian ducts.
• Class IV anomalies are bicornuate uteri that demonstrate incomplete fusion of the
superior segments of the uterovaginal canal.
• Class V anomalies are septate uteri that represent partial or complete nonresorption
of the uterovaginal septum after fusion of the paramesonephric ducts. As a result, a
fibrous septum may divide the endometrial cavity alone (partial septate) or may
extend into the endocervical canal (complete septate). Septate uterus is the most
common Müllerian duct anomaly (55%) and is associated with some of the poorest
reproductive and obstetric outcomes.
• Class VI anomalies are arcuate uteri that result from near complete resorption of the
septum.
• Class VII anomalies comprise sequelae of in utero diethylstilbestrol exposure.
Imaging Findings
I t is important to differentiate septate uterus that may require hysteroscopicmetroplasty from anomalies that may require reconstructive transabdominal surgery,
such as bicornuate uterus. Endovaginal ultrasonography (especially
threedimensional imaging with coronal reconstruction) and MRI can be used to assess
both the external contour of the fundus (this is the most important feature for
distinguishing a septate uterus from a bicornuate uterus) and the nature of the
dividing tissue. I n septate uterus (Figures S20-1, S20-2, and S20-3), the fundal contour
is normal, flat, or slightly concave with indentation 1 cm or less in depth. I n
bicornuate uterus, the fundal cleft is deeper than 1 cm. The imaging characteristic of
the tissue separating the two endometrial cavities is a less reliable feature than the
external shape of the uterus. Typically, a fibrous septum defines a septate uterus,
whereas the myometrial septum occurs only in bicornuate uterus. However, a partial
septum may also contain myometrium in septate uterus. A nother helpful feature is
the intercornual angle. I n septate uterus, the cornual angle on hysterosalpingograms
is typically 75 degrees or less, whereas this angle is usually greater than 105 degrees in
bicornuate uterus or uterus didelphys. On MRI in a coronal oblique plane of the
uterus, the intercornual distance is typically 4 cm or less in septate uterus. I n
bicornuate uterus or uterus didelphys, this intercornual distance is more than 4 cm.
References
1. The American Fertility Society classifications of adnexal adhesions, distal tubal
occlusion, tubal occlusion secondary to tubal ligation, tubal pregnancies,
Müllerian anomalies and intrauterine adhesions. Fertil Steril. 1988;49(6):944–955.
2. Troiano RN, McCarthy SM. Mullerian duct anomalies: imaging and clinical
issues. Radiology. 2004;233(1):19–34.
3. Zreik TG, Troiano RN, Ghoussoub RA, Olive DL, Arici A, McCarthy SM.
Myometrial tissue in uterine septa. J Am Assoc Gynecol Laparosc. 1998;5(2):155–160.
Cross-Reference
1. Genitourinary Imaging: The Requisites, 2nd ed, 263–264.Case 21
FIGURE 21-1FIGURE 21-2
History
A 49-year-old man has a 6-month history of progressive weakness and dizziness.
1. Which of the following would be included in the differential diagnosis for the
imaging findings presented? (Choose all that apply.)
A. Renal cell carcinoma
B. Adrenocortical carcinoma
C. Leiomyosarcoma of the inferior vena cava (IVC)
D. Renal sarcoma
2. Which of the following tumors is most commonly associated with tumor
thrombus in the IVC?
A. Adrenocortical carcinoma
B. Renal angiomyolipoma
C. Renal cell carcinoma
D. Transitional cell carcinoma
3. Which of the following findings is most suggestive of tumor thrombus as
opposed to bland thrombus within the renal vein and IVC?
A. Filling defect within the renal vein/IVC with enlargement of these veins
B. Transient filling defect within the IVC
C. Filling defect within the renal vein/IVC, which demonstrates contrast
enhancement
D. Filling defect within the renal vein/IVC with increased collateral veins in the
retroperitoneum
4. Which of the following T stagings in TNM (tumor, node, metastasis)
classification (2010 American Joint Committee on Cancer) applies to the