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The Teaching Files: Head and Neck Imaging, by Dr. Girish Fatterpekar, MD, with its easy-to-use, templated organization, well-presented case reviews, and high-yield imaging examples, aims to sharpen your diagnostic skills. Exquisitely illustrated key imaging features and relevant, succinct discussions of differential diagnoses provide you with the necessary tools required to feel confident when reading head and neck cases.

  • Quickly review easy-to-read templated chapters with 2-4 images per case, 600+ high-quality illustrations in all.
  • Keep current in your practice with discussions of the most up-to-date radiologic modalities and technologies.
  • Get suggested readings of the most important references for more information on specific topics.
  • Review discussions of similar cases and resolve challenging diagnostic questions.
  • Reference demographics/clinical history, findings, discussion, characteristic/clinical features, radiologic findings, differential diagnosis, and suggested readings for every case.

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The Teaching Files
Head and Neck
Girish M. Fatterpekar, MBBS, DMRD, DNB, MD
Assistant Professor Radiology, James J. Peters VA Medical
Center, Mount Sinai Medical Center, New York, NY
Peter M. Som, MD, FACR
Professor of Radiology, Otolaryngology, and Radiation
Oncology, Chief of the Head and Neck Imaging Section,
Mount Sinai Medical Center, New York, NY
Thomas P. Naidich, MD, FACR
Professor of Radiology and Neurosurgery, Director of
Neuroradiology, Irving and Dorothy Regenstreif Research
Professor of Neuroscience (Neuroimaging), Mount Sinai
Medical Center, New York, NY
S a u n d e r sFront matter
THE TEACHING FILES: Head and Neck Imaging
The teaching files
Head and Neck
Girish M. Fatterpekar, MBBS, DMRD, DNB, MD, Assistant Professor
Radiology, James J. Peters VA Medical Center, Mount Sinai Medical Center,
New York, NY
Peter M. Som, MD, FACR, Professor of Radiology, Otolaryngology, and
Radiation Oncology, Chief of the Head and Neck Imaging Section, Mount
Sinai Medical Center, New York, NY
Thomas P. Naidich, MD, FACR, Professor of Radiology and Neurosurgery,
Director of Neuroradiology, Irving and Dorothy Regenstreif Research
Professor of Neuroscience (Neuroimaging), Mount Sinai Medical Center,
New York, NY<
<
Copyright
1600 John F. Kennedy Blvd.
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THE TEACHING FILES: HEAD AND NECK IMAGING
ISBN:9781416060598
Copyright © 2011 by Saunders, an imprint of Elsevier Inc.
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Notices
Knowledge and best practice in this eld 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 identi ed, readers are
advised to check the most current information provided (i) on procedures
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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.
Library of Congress Cataloging-in-Publication Data or Control Number
(in STL)
Fatterpekar, Girish M.
The teaching files : Head and neck / Girish M. Fatterpekar. – 1st ed.
p. ; cm.
Other title: Head and neck
ISBN 978-1-4160-6059-8
1. Head–Radiography–Case studies. 2. Neck–Radiography–Case studies. I.
Title. II. Title: Head and neck.
[DNLM: 1. Head–pathology–Case Reports. 2. Head–radiography–Case
Reports. 3. Diagnosis, DiEerential–Case Reports. 4. Diagnostic Imaging–methods–
Case Reports. 5. Neck–pathology–Case Reports. 6. Neck–radiography–Case
Reports. WE 705 F254t 2010]
RC936.F38 2010
617.5'107572–dc22
2010010095
Acquisitions Editor: Pamela Hetherington
Developmental Editor: Lora Sickora
Publishing Services Manager: Anitha Raj
Project Manager: Marquita Parker/Kiruthiga Kasthuriswamy
Design Direction: Steven Stave
Printed in United States of America
Last digit is the print number: 9 8 7 6 5 4 3 2 1 D e d i c a t i o n
To my parents, Manohar and Sulabha who instilled in me that hard work,
sincerity and dedication hold the keys to success
To my wife Monali, for her unwavering support
To my son Tanush, and nieces Isha and Nova for whom this book might serve as
an inspiration
Be curious always! For knowledge will not acquire you; you must acquire it.
- Sudie Back


Preface
Head and neck radiology has always been considered a challenging imaging
territory. This largely stems from inadequate exposure in this eld. Case in-point,
how many residents go through a dedicated “head and neck radiology” rotation
during residency? In addition, the supposedly complex anatomy of this region
makes head and neck radiology appear daunting. However, a focused systematic
approach as outlined in this case collection, can make head and neck radiology
explicable and interesting.
Toward this end are presented a wide array of common, and some uncommon
pathologies. Consider reading a few cases a day, and in a short period of time, you
will become much more comfortable with the subject.
This text, like the other volumes in the Expert Radiology Series, has been
designed to exemplify key concepts in imaging in a proven easy-to-digest
casebased format. It does not provide an exhaustive review of head and neck
radiology. It focuses on the salient imaging features. For a more comprehensive
discussion on the subject, the reader is referred to texts such as Head and Neck
Imaging by Som and Curtin.
There are 14 sections in this volume, each of which deals with a particular
anatomic region such as orbit, nasal cavity and paranasal sinuses, facial trauma,
etc. Cases presented in each of these sections have been organized in a particular
format providing clinical history, illustrative images, and a concise discussion of
that particular entity including background information, characteristic radiologic
ndings, and discussion of di, erential diagnosis. A suggested reading section
provides the reader with appropriate reference material.
Images are the very essence of radiology. Keeping this in mind, this book
provides more than 600 carefully selected images, obtained largely from the
Interesting Case Collection (otherwise known as the Som collection) of Mount Sinai
Medical Center, one of the premier institutions of otolaryngology in the country.
While the book has been designed speci cally for radiology and otolaryngology
residents, as well as neuroradiology Fellows, it should also prove to be of great
value in honing the interpretational skills of all practicing head and neck
radiologists.
I would like to take this opportunity to thank my mentors par excellence Drs.
Som and Naidich, who despite their busy schedule provided me with invaluable
tips, and without whose help, this book would never have been complete.
It is my genuine hope that this book will be informative and instructive. I will
consider my e, orts worthwhile only if you, the reader, nd it useful. Feedback is
important and will be much appreciated.
Employ your time in improving yourself by other men's writings, so that you shall
gain easily what others have labored hard for ~ Socrates
Girish Fatterpekar, MD#
#
Acknowledgements
Girish M. Fatterpekar
My deepest gratitude to my mentors whose guidance only helped me better
myself. In particular, I would like to thank Burton Drayer, Thomas Naidich, Peter
Som, Mauricio Castillo, Suresh Mukherji, Manu Shro , and Ravi Ramakantan.
Neuroradiology including Head and Neck radiology would never have been as
exciting and enriching without your teaching.
I also want to acknowledge the sta at Elsevier for their patience and support in
making this text possible, especially Rebecca Gaertner, Pamela Hetherington and
Lora Sickora. It was a pleasure working with you.In Memorium
This book is dedicated to Prashant Shetty, neuroradiologist extraordinaire, a
mentor and colleague dearly missed.Table of Contents
Front matter
Copyright
Dedication
Preface
Acknowledgements
In Memorium
Chapter 1: Orbit
Chapter 2: Nasal Cavity and Paranasal Sinuses
Chapter 3: Facial Fractures
Chapter 4: Temporal Bone
Chapter 5: Sella, Cranial Vault, Skull Base and Brain
Chapter 6: Salivary Glands
Chapter 7: Oral Cavity and Floor of Mouth
Chapter 8: Masticator Space including Jaws and Temporomandibular
Joint
Chapter 9: Pharynx
Chapter 10: Larynx
Chapter 11: Parapharyngeal Space
Chapter 12: Thyroid and Parathyroid Glands
Chapter 13: Brachial Plexus
Chapter 14: Neck Miscellaneous
Index of Cases
IndexOrbit
Case 1
Demographics/clinical history
The patient is a 52-year-old man with trauma.
Findings
An axial computed tomography (CT) scan (Fig. 1) of the orbits shows focal
outpouching from the posterior aspect of both ocular globes. An increase in the
anteroposterior dimension of both globes is also noted. In a di#erent patient, an
axial CT scan (Fig. 2) through the orbits shows focal outpouching along the
posterior aspect of both ocular globes. The increased density seen within the
outpouchings is likely a technique-related artifact and does not represent
hemorrhage.
Figure 1 Axial CT scan of orbits shows focal outpouching from posterior aspect of
both ocular globes. Also noted is an increase in anteroposterior dimension of both
globes. The increased density seen within the outpouchings is likely a
techniquerelated artifact and does not represent hemorrhage.Figure 2 In a di#erent patient, axial CT scan through orbits shows focal
outpouching along posterior aspect of both ocular globes.
Discussion
Definition/Background
Staphyloma refers to thinning and stretching of the scleral-uveal coats of the ocular
globe. This condition most commonly occurs posteriorly, with progressive myopia
being the most common cause. Anterior staphylomas are less common and are seen
secondary to in) ammation or infection of the sclerocorneal lining of the eye. Other
types of staphylomas include intercalary, ciliary, and equatorial types, which are
uncommon.
Characteristic Clinical Features
Most often, staphylomas are detected during evaluation of myopia. Occasionally,
these are identi, ed with glaucoma, scleritis, and trauma. Staphylomas have a high
risk for advanced chorioretinal degeneration, choroid retraction from the optic
disk, and posterior vitreous detachments. These changes can lead to choroidal
hemorrhage and retinal detachment, which can result in loss of vision.
Characteristic Radiologic Findings
A focal bulge is seen along the ocular globe, most commonly along its posterior
aspect. Most often, this finding is associated with a myopic globe.
Differential Diagnosis
Coloboma
Discussion
Based strictly on imaging, it can be di. cult to distinguish coloboma from
staphyloma.
Diagnosis
The diagnosis is “staphyloma.”
Suggested Readings
Osborne D.R., Foulks G.N. Computed tomographic analysis of deformity and
dimensional changes in the eyeball. Radiology. 1984;153:669-674.
Smith M., Castillo M. Imaging and differential diagnosis of the large eye.
RadioGraphics. 1994;14:721-728.Swayne L.C., Garfinkle W.B., Bennett R.H. CT of posterior ocular staphyloma in axial
myopia. Neuroradiology. 1984;26:241-243.
Case 2
Demographics/clinical history
The patient is a 14-year-old girl with right-sided convergent strabismus.
Findings
An axial computed tomography (CT) scan (Fig. 1) of the orbits shows a focal defect
at the site of the optic disk.
Figure 1 Axial CT scan of orbits shows focal defect (arrowheads) at the site of the
optic disk.
Discussion
Definition/Background
Coloboma (from the Greek koloboun, “to mutilate”) is de, ned as an absence or
defect of some ocular tissue, usually resulting from improper closure of the fetal
intraocular , ssure. Any part of the eye, including the lens, eyelid, choroid, retina,
or optic disk, may be involved. When coloboma involves the optic disk, it is known
as morning glory anomaly.
Characteristic Clinical Features
Because optic disk colobomas usually are associated with scotomas or blindness,
convergent strabismus is common. On funduscopy, the disk is enlarged and
excavated, and it has a central core of white tissue, surrounded by an elevated
annulus of pigmented chorioretinal tissue. This pattern was , rst described as amorning glory disk by Kindler in 1970 because its appearance was similar to the
morning glory flower.
Characteristic Radiologic Findings
The main finding on imaging is a funnel-shaped defect at the site of the optic disk.
Less Common Radiologic Manifestations
Other associated , ndings can include optic nerve atrophy, basal (particularly
sphenoidal) encephalocele, and agenesis of the corpus callosum.
Differential Diagnosis
Staphyloma
Discussion
Staphyloma refers to localized ectasia of the globe. Based on imaging, it can be
di. cult to distinguish a staphyloma from coloboma. Staphyloma does not have the
classic funduscopic appearance of a coloboma.
Diagnosis
The diagnosis is “coloboma.”
Suggested Readings
Kindler P. Morning glory syndrome: Unusual congenital optic disc anomaly. Am J
Ophthalmol. 1970;69:376-384.
Murphy B.L., Griffin J.F. Optic nerve coloboma (morning glory syndrome): CT
findings. Radiology. 1994;191:59-61.
Supplementary Data
a. Click here to see labeled and unlabeled image views for this case.
Case 3
Demographics/clinical history
The patient is a 61-year-old man with visual field defects.
FindingsAxial computed tomography (CT) scan (Fig. 1) of the orbits shows dense, discrete,
and punctate foci in the region of the optic disks bilaterally.
Figure 1 Axial CT scan of orbits shows dense, discrete, and punctate foci (arrows)
in region of the optic disks bilaterally.
Discussion
Definition/Background
Optic nerve head drusen are composed of small conglomerates of
mucopolysaccharides and proteinaceous material in the region of the optic disks,
which calcify with advancing age. They are bilateral in about 70% of cases and
can be inherited as an autosomal dominant trait with variable penetrance.
Characteristic Clinical Features
Patients with drusen usually are asymptomatic. Because of their location below the
surface of the disk, drusen sometimes can lead to a misdiagnosis of papilledema.
Rarely, some patients present with visual field defects.
Characteristic Radiologic Findings
Dense, discrete, punctate, or rounded foci without any associated soft tissue mass in
the region of the optic disk are diagnostic for optic nerve head drusen.
Diagnosis
The diagnosis is “optic nerve head drusen.”Suggested Reading
Ramirez H., Blatt E.S., Hibri N.S. Computed tomographic identification of calcified
optic nerve drusen. Radiology. 1983;148:137-139.
Supplementary Data
a. Click here to see labeled and unlabeled image views for this case.
Case 4
Demographics/clinical history
The patient is a 24-year-old woman with proptosis.
Findings
Axial T1-weighted magnetic resonance imaging (MRI) (Fig. 1) shows enlargement
of the muscle bellies of the medial recti bilaterally, with sparing of the anterior
tendinous insertions. Coronal T1-weighted MRI (Fig. 2), coronal T2-weighted MRI
(Fig. 3), and contrast-enhanced fat-suppressed coronal T1-weighted MRI (Fig. 4)
show enlarged extraocular muscles (EOMs), including predominantly the superior
and medial recti bilaterally, the superior oblique, and the right inferior rectus. The
left inferior rectus is much smaller than normal, which likely re) ects a more
chronic form of the disease. The left EOMs appear hyperintense and show
asymmetric enhancement. This appearance suggests active, ongoing in) ammation
and is a good prognostic indicator for a response to steroid therapy.
Figure 1 Axial T1-weighted MRI shows enlargement of muscle bellies of medial
recti bilaterally, with sparing of anterior tendinous insertions (arrow).Figure 2 Coronal T1-weighted MRI shows enlarged EOMs, including superior and
medial recti, superior oblique bilaterally, and right inferior rectus. Left inferior
rectus is much smaller than normal, which likely re) ects a more chronic form of the
disease.
Figure 3 Coronal T2-weighted MRI shows bilateral involvement, with left EOM
appearing asymmetrically enlarged and exhibiting hyperintense signal when
compared with right EOM.
Figure 4 Contrast-enhanced fat-suppressed coronal T1-weighted MRI shows
asymmetric enhancement of the left EOMs. This suggests active ongoinginflammation and is a good prognostic indicator for response to steroid therapy.
Discussion
Definition/Background
Graves disease is an autoimmune disease characterized by hyperthyroidism. It is
the most common cause of hyperthyroidism in the United States, and it frequently
affects women 20 to 45 years old.
Characteristic Clinical Features
Classically, patients present with hyperthyroidism associated with di#use
enlargement of the gland, in, ltrative, orbitopathy, or, less likely, in, ltrative
dermopathy and acropachy. Thyroid orbitopathy results from binding of the
immune complexes to the EOMs, inciting an in) ammatory reaction and causing
muscle enlargement and exophthalmos. In the chronic stage of the disease, , brosis
results from degeneration of the muscle , bers, with secondary fatty replacement
and restrictive myopathy.
Characteristic Radiologic Findings
Exophthalmos is typically bilateral. Enlargement of the muscle bellies occurs with
sparing of the tendinous insertions. Although all EOMs can be involved, the inferior
rectus is involved most commonly, followed by the medial rectus and the superior
rectus. Patients have increased orbital fat. Bilateral enlargement of the muscle
bellies without involvement of the tendinous insertions is pathognomonic.
Less Common Radiologic Manifestations
Increased signal intensity may be seen within the muscles on T2-weighted MRI with
associated enhancement on postcontrast images. This , nding re) ects an underlying
acute in) ammatory process that usually has a good response to steroid therapy.
Involvement of the levator palpebrae superioris is occasionally seen and is the
cause of upper eyelid retraction in patients with Graves disease.
Differential Diagnosis
EOM enlargement by pseudotumor, myositis, infections such as Lyme disease, or
metastasis
Increased orbital fat from obesity, steroid use, or diabetes
Discussion
Pseudotumor, myositis, infections such as Lyme disease, and metastasis are likely tobe unilateral and involve the muscle bellies and their tendinous insertions. With
metastasis, focal enhancement within the muscle may be seen. Obesity, steroid use,
and diabetes can cause increased orbital fat content without involvement of the
EOMs.
Diagnosis
The diagnosis is “Graves disease with characteristic thyroid orbitopathy.”
Suggested Readings
Charkes N.D., Maurer A.H., Siegel J.A., et al. MR imaging in thyroid disorders:
Correlation of signal intensity with Graves disease activity. Radiology.
1987;164:491-494.
Ohnishi T., Noguchi S., Murakami N., et al. Levator palpebrae superioris muscle: MR
evaluation of enlargement as a cause of upper eyelid retraction in Graves disease.
Radiology. 1993;188:115-118.
Ohnishi T., Noguchi S., Murakami N., et al. Extraocular muscles in Graves
ophthalmopathy: Usefulness of T2 relaxation time measurements. Radiology.
1994;190:857-862.
Supplementary Data
a. Click here to see labeled and unlabeled image views for this case.
Case 5
Demographics/clinical history
The patient is a 23-year-old man with sarcoidosis.
Findings
Coronal T1-weighted magnetic resonance imaging (MRI) (Fig. 1), coronal
T2weighted MRI (Fig. 2), and contrast-enhanced fat-suppressed coronal T1-weighted
MRI (Fig. 3) show enlarged lacrimal glands that exhibit homogeneous
enhancement.Figure 1 Coronal T1-weighted MRI shows bilateral, enlarged lacrimal glands
(arrows), which appear slightly hyperintense compared with adjacent extraocular
muscles.
Figure 2 Coronal T2-weighted MRI shows bilateral, enlarged lacrimal glands,
which appear slightly hypointense compared with adjacent extraocular muscles.Figure 3 On contrast-enhanced fat-suppressed coronal T1-weighted MRI,
nearhomogeneous enhancement is seen of enlarged lacrimal glands (arrows).
Discussion
Definition/Background
Sarcoidosis is a chronic, granulomatous disease of unknown origin that a#ects
many organ systems, most commonly the lungs and the mediastinal lymph nodes.
In the head and neck, sarcoidosis can a#ect the cervical chain of lymph nodes.
Extranodal head and neck involvement occurs in about one-third of patients, and
the preferred sites are the orbit, including almost any part of the globe, the optic
nerve, and the lacrimal gland; the parotid gland; and submucosa of the upper
respiratory tract.
Characteristic Clinical Features
Patients may be totally asymptomatic or may present with nonspeci, c symptoms,
such as malaise, fever, erythema nodosum, or lymphadenopathy. Noncaseating
granulomas containing asteroid bodies, Schaumann bodies, and
HamasakiWesenberg inclusions are pathognomonic. A positive Kveim test result and elevated
angiotensin-converting enzyme levels support the diagnosis of sarcoidosis.
Characteristic Radiologic Findings
Unilateral or bilateral enlargement of the lacrimal glands is seen. Typically, the
enlarged glands appear hyperintense to the extra-ocular muscles on T1-weighted
image (WI), hypointense to the extra-ocular muscles on T2WI, and exhibit
homogenous enhancement following contrast administration. In addition, patientsmay have enlarged, non-necrotic cervical lymph nodes, with multiple, enlarged
intraparotid lymph nodes. Calci, cation of the lymph nodes never occurs in the
head and neck region. Imaging may show di#use submucosal involvement or
nodular involvement of the submucosa of the upper respiratory tract.
Differential Diagnosis
Enlarged lacrimal gland
Discussion
Lacrimal gland enlargement may be unilateral (e.g., pleomorphic adenoma,
adenoid cystic carcinoma, pseudotumor) or bilateral (e.g., lymphoma, Sjögren
syndrome, Wegener granulomatosis). The associated characteristic chest , ndings of
bilateral hilar lymphadenopathy and interstitial lung disease suggest the diagnosis
of sarcoidosis. If the characteristic chest , ndings are absent, biopsy is indicated.
Usually, sarcoidosis responds well to high-dose corticosteroids.
Diagnosis
The diagnosis is “sarcoidosis involving the lacrimal glands.”
Suggested Readings
Mafee M.F., Dorodi S., Pai E. Sarcoidosis of the eye, orbit, and central nervous system:
Role of MR imaging. Radiol Clin North Am. 1999;37:73-87.
Som P.M., Krespi Y.P. Laryngeal sarcoid. Radiology. 1979;133:341-342.
Supplementary Data
a. Click here to see labeled and unlabeled image views for this case.
Case 6
Demographics/clinical history
The patient is a 32-year-old woman with sicca-like symptoms.
Findings
Coronal T1-weighted magnetic resonance imaging (MRI) (Fig. 1), coronal
T2weighted MRI (Fig. 2), axial T2-weighted MRI (Fig. 3), and contrast-enhanced
fatsuppressed coronal T1-weighted MRI (Fig. 4) show enlarged, homogeneously
enhancing bilateral lacrimal glands.Figure 1 Coronal T1-weighted MRI shows homogeneous enlargement of both
lacrimal glands.
Figure 2 Coronal T2-weighted MRI shows lobulated enlarged lacrimal glands.Figure 3 Axial T2-weighted MRI shows enlarged lacrimal glands with no evidence
for any bony destruction or extension into adjacent soft tissues.
Figure 4 Contrast-enhanced fat-suppressed coronal T1-weighted MRI shows
welldefined, near-homogeneous enhancement of both lacrimal glands.
Discussion
Definition/Background
Sjögren syndrome is a systemic autoimmune disorder characterized by lymphocytic
in, ltration of the exocrine glands. Two varieties of Sjögren syndrome are known:
(1) primary Sjögren syndrome, in which no underlying autoimmune disorder is
present, and (2) secondary Sjögren syndrome, which is usually associated withseveral connective tissue diseases, of which rheumatoid arthritis is most common.
Characteristic Clinical Features
Most patients present with sicca symptoms, such as xerophthalmia (dry eyes),
xerostomia (dry mouth), and parotid gland enlargement.
Characteristic Radiologic Findings
Bilateral lacrimal gland enlargement, which can be evaluated on computed
tomography (CT) and MRI, is a typical imaging , nding of Sjögren syndrome.
Associated bilateral parotid gland involvement showing di#use globular (cystic)
changes within the glands is considered diagnostic of the disease. To evaluate the
parotid glands, MRI is more speci, c than CT in establishing the diagnosis. In the
early stages of the disease, even MRI can be normal. In such cases, a sialogram can
show punctate changes within the ductal system, which in an appropriate clinical
setting is diagnostic.
Less Common Radiologic Manifestations
Occasionally, lymphomas can develop.
Differential Diagnosis
Lymphoma
Sarcoidosis
Pseudotumor
Discussion
Based on imaging alone, it can be di. cult to distinguish the individual etiologies
for bilateral lacrimal gland enlargement. Fatty replacement, if seen within the
enlarged lacrimal glands, has been reported as being highly suggestive of Sjögren
syndrome. Associated salivary gland involvement as outlined earlier is also
diagnostic of Sjögren syndrome. If only lacrimal gland enlargement is seen, the
clinical history can help suggest the diagnosis.
Diagnosis
The diagnosis is “Sjögren syndrome with bilateral lacrimal gland enlargement.”
Suggested Readings
Izumi M., Eguchi K., Uetani M., et al. MR features of the lacrimal gland in Sjögren’s
syndrome. AJR Am J Roentgenol. 1998;170:1661-1666.Mafee M.F. Orbit: Embryology, anatomy, and pathology. In: Som P.M., Curtin H.D.,
editors. Head and Neck Imaging. 4th ed. St. Louis: Mosby; 2003:529-654.
Tonami H., Ogawa Y., Matoba M., et al. MR sialography in patients with Sjögren
syndrome. AJNR Am J Neuroradiol. 1998;19:1199-1203.
Case 7
Demographics/clinical history
The patient is a 26-year-old woman with right eye pain and acute loss of vision.
Findings
Coronal T2-weighted magnetic resonance imaging (MRI) (Fig. 1) shows a mildly
thickened, minimally hyperintense right optic nerve. Contrast-enhanced
fatsuppressed coronal T1-weighted MRI (Fig. 2) shows asymmetric enhancement of
the right optic nerve. Axial T2-weighted MRI (Fig. 3) through the brain at the level
of the ventricles shows multiple, well-de, ned foci of increased signal intensity seen
within the perivenular regions of the periventricular white matter.
Figure 1 Coronal T2-weighted MRI shows mildly thickened, minimally
hyperintense right optic nerve (arrowhead).Figure 2 Contrast-enhanced fat-suppressed coronal T1-weighted MRI shows
asymmetric enhancement (arrow) of right optic nerve.
Figure 3 Axial T2-weighted MRI through the brain at the level of the ventricles
shows multiple well-de, ned foci of increased signal intensity seen within
perivenular regions of periventricular white matter.
DiscussionDefinition/Background
Optic neuritis is acute in) ammation of the optic nerve. The most common cause of
optic neuritis is multiple sclerosis. Neuromyelitis optica, also known as Devic
disease, is a rare demyelinating condition that a#ects the optic nerve. It is
frequently misdiagnosed as multiple sclerosis, but it is a separate entity; the
demyelinating disease process involves the optic nerves and the spinal cord, but not
the brain parenchyma. Other conditions that can cause in) ammation of the optic
nerve include Lyme disease; tuberculosis; syphilis; and viral infections such as
human immunode, ciency virus (HIV), herpes, and cytomegalovirus. Rarely,
inflammation of the optic nerve can occur secondary to radiation therapy.
Characteristic Clinical Features
The classic triad of optic neuritis consists of (1) acute loss of vision, (2) eye pain,
and (3) impairment of accurate color vision. Seventy percent of cases are
unilateral. In children, optic neuritis is rare, but when seen, it is usually bilateral.
Most patients recover spontaneously, although recovery can take months. Relapsing
episodes can occur, especially in demyelinating conditions.
Characteristic Radiologic Findings
MRI is the gold standard for evaluation of optic neuritis. Typically, a slightly
thickened optic nerve that appears hyperintense on T2-weighted MRI is seen.
Contrast-enhanced fat-suppressed T1-weighted MRI shows enhancement of the
involved segment of the optic nerve.
Differential Diagnosis
Optic nerve sheath meningioma
Optic nerve glioma
Lyme disease and other infective conditions
Radiation-therapy induced change
Discussion
In cases of optic nerve sheath meningioma, enhancement is typically seen around
the optic nerve. The optic nerve itself is typically spared. This enhancement has
been described as the tram-track sign of optic nerve sheath meningiomas. The
thickening of the optic nerve seen in optic nerve glioma can be slightly more
pronounced than in optic neuritis. Optic nerve gliomas are strongly associated with
neuro, bromatosis 1. Pain is not a presenting feature of optic nerve glioma, whereas
it is one of the clinical hallmarks of optic neuritis. Based on imaging, it can bedi. cult to distinguish Lyme disease, other infective conditions, and
radiationinduced in) ammatory change of the optic nerve from optic neuritis. Correlation
with clinical history can be helpful.
Diagnosis
The diagnosis is “optic neuritis.”
Suggested Readings
Eggenberger E.R. Inflammatory optic neuropathies. Ophthalmol Clin North Am.
2001;14:73-82.
Filippi M., Rocca M.A. MR imaging of Devic’s neuromyelitis optica. Neurol Sci.
2004;25:S371-S373.
Jackson A., Patankar T., Laitt R.D. Intracanalicular optic nerve meningioma: A serious
diagnostic pitfall. AJNR Am J Neuroradiol. 2003;24:1167-1170.
Rocca M.A., Hickman S.J., Bo L., et al. Imaging the optic nerve in multiple sclerosis.
Mult Scler. 2005;11:537-541.
Tien R.D., Hesselink J.R., Szumowski J. MR fat suppression combined with Gd-DTPA
enhancement in optic neuritis and perineuritis. J Comput Assist Tomogr.
1991;15:223-227.
Supplementary Data
a. Click here to see labeled and unlabeled image views for this case.
Case 8
Demographics/clinical history
The patient is a 46-year-old man with diplopia and a history of skin rash in the
recent past.
Findings
Contrast-enhanced fat-suppressed coronal magnetic resonance imaging (MRI) (Fig.
1) shows di#use homogeneous thickening of the extraocular muscles of the right
orbit. Contrast-enhanced fat-suppressed axial MRI (Fig. 2) shows sparing of the
tendinous insertions. A follow-up study 3 months after treatment with
contrastenhanced fat-suppressed coronal MRI (Fig. 3) shows normal-appearing extraocular
muscles of the right orbit. Contrast-enhanced fat-suppressed axial MRI (Fig. 4)
confirms this finding.Figure 1 Contrast-enhanced fat-suppressed coronal MRI shows di#use
homogeneous thickening of extraocular muscles of the right orbit.
Figure 2 Contrast-enhanced fat-suppressed axial MRI shows sparing of tendinous
insertions.
Figure 3 Follow-up study 3 months after treatment with contrast-enhanced
fatsuppressed coronal MRI shows normal-appearing extraocular muscles of right orbit.Figure 4 Contrast-enhanced fat-suppressed axial MRI confirms this finding.
Discussion
Definition/Background
Lyme disease is the most common arthropod-borne infection in the United States. It
is caused by Borrelia burgdorferi. Multiple organ systems can be involved.
Characteristic Clinical Features
The disease can be divided into three clinical stages. Stage I is classically
characterized by a centrifugally expanding erythematous annular rash, erythema
migrans, that occurs at the site of the tick bite. Stage II begins weeks to several
months after initial infection, with multiorgan involvement and a predilection for
the cardiovascular and central nervous system. Stage III, the chronic phase of Lyme
disease, occurs months after the initial onset and is characterized by involvement of
the joints, peripheral nervous system, and subcutaneous tissues. Ocular
manifestation is uncommon. Orbital manifestations include conjunctivitis,
keratosis, and nonspeci, c in) ammatory syndromes involving the optic nerve and
the extraocular muscles.
Characteristic Radiologic Findings
Nonspeci, c imaging , ndings are seen. Extraocular muscle thickening and
enhancement may be seen. Optic nerve involvement in the early stages may be
characterized by edema and enhancement. Chronic stages may show optic nerve
atrophy.
Differential Diagnosis
Extraocular Muscle Involvement
Thyroid orbitopathy Pseudotumor
Lymphoma
Optic Nerve Involvement
Optic neuritis
Optic nerve glioma
Discussion
Thyroid orbitopathy is characterized by bilateral enlargement of the extraocular
muscles with sparing of the tendinous insertions. Usually, pseudotumor and
lymphoma will involve the tendinous insertions as well. However, sometimes, based
on imaging alone, it can be di. cult to distinguish the various etiologies.
Correlation with the clinical history can help narrow the differential diagnosis.
Diagnosis
The diagnosis is “orbital Lyme disease.”
Suggested Readings
Duray P.H. Clinical pathologic correlations of Lyme disease. Rev Infect Dis.
1989;2:1487-1493.
Fatterpekar G.M., Gottesman R.I., Sacher M., et al. Orbital Lyme disease: MR imaging
before and after treatment: Case report. AJNR Am J Neuroradiol. 2002;23:657-659.
Steere A. Lyme disease. N Engl J Med. 1989;321:586-596.
Case 9
Demographics/clinical history
The patient is a 28-year-old man with left orbital pain, conjunctival congestion,
and limited ocular motility.
Findings
An axial computed tomography (CT) bone window image (Fig. 1) shows a
peripherally enhancing collection in the left upper eyelid and periorbital region
with extension into the post-septal compartment. Axial T1-weighted magnetic
resonance imaging (MRI) (Fig. 2), axial T2-weighted MRI (Fig. 3), and
contrastenhanced fat-suppressed axial T1-weighted MRI (Fig. 4) show mucosal thickeninginvolving the left ethmoid sinuses. Also noted is a peripherally enhancing collection
along the left lamina papyracea suggestive of a subperiosteal abscess. Bowing and
thickening of the left medial rectus muscle suggestive of myositis is noted. Minimal
secondary proptosis is seen.
Figure 1 Contrast-enhanced axial CT scan demonstrates a peripherally enhancing
collection in the left upper eyelid and periorbital region with extension into the
post-septal compartment (arrows). These , ndings are suggestive of left periorbital
abscess with post-septal extension.
Figure 2 In a di#erent patient, axial T1-weighted MRI shows near-complete
opaci, cation of left ethmoid sinuses with extension of in) ammatory soft tissue into
adjacent left orbit.Figure 3 Axial T2-weighted MRI shows in) ammatory mucosal thickening
involving left ethmoid sinuses with associated contiguous involvement of left orbit.
Figure 4 Contrast-enhanced fat-suppressed axial T1-weighted MRI shows mucosal
thickening involving left ethmoid sinuses. Also noted is a peripherally enhancing
collection along the left lamina papyracea suggestive of subperiosteal abscess.
Bowing and thickening of left medial rectus muscle suggestive of myositis is noted.
Minimal secondary proptosis is seen.
Discussion
Definition/Background
Ocular cellulitis can be broadly classi, ed into preseptal cellulitis and postseptal
cellulitis, depending on the location of the infection with respect to the orbital
septum. Postseptal cellulitis has been referred to as orbital cellulitis. Preseptal
cellulitis tends to be a less severe disease than orbital cellulitis (postseptal
cellulitis). Orbital cellulitis has a higher morbidity, requires aggressive treatment,
and may require surgical intervention, whereas preseptal cellulitis usually is
managed conservatively. The most common cause of orbital cellulitis is sinusitis.
External ocular infection and trauma are other causes of orbital cellulitis.
Characteristic Clinical Features
Patients usually present with orbital pain, swelling, and erythema. Patients with
postseptal cellulitis also complain of limitation of ocular motility and proptosis.
Characteristic Radiologic Findings
Contrast-enhanced CT is the diagnostic imaging study of choice. MRI may be
obtained in equivocal cases or to evaluate for certain complications, such as
cavernous sinus thrombosis. Preseptal cellulitis shows soft tissue thickening in the
periocular soft tissues anterior to the orbital septum. Postseptal cellulitis shows softtissue thickening and stranding in the postseptal compartment of the orbit. A
common associated finding is sinusitis.
Key Anatomy Point
The orbital septum is a thin membranous structure that forms the anterior
boundary of the orbit. It extends from the orbital rims to the eyelids. In the upper
lid, it blends with the levator palpebrae superioris; in the lower lid, it blends with
the tarsal plate. Although the membrane is di. cult to identify on imaging, it can
be roughly identi, ed as the region that separates the intraorbital fat from the
eyelid fat and adjacent orbicularis oculi muscle.
Less Common Radiologic Manifestations
Abscess may be seen within the lid in preseptal cellulitis. A subperiosteal abscess
may be seen in postseptal cellulitis. Cavernous sinus thrombosis is a dreaded
complication and is only rarely seen.
Diagnosis
The diagnosis is “orbital cellulitis.”
Suggested Readings
Eustis H.S., Mafee M.F., Walton C., et al. MR imaging and CT of orbital infections and
complication in acute rhinosinusitis. Radiol Clin North Am. 1998;36:1165-1183.
Hoffmann K.-T., Hosten N., Lemke A.-J., et al. Septum orbitale: High-resolution MR in
orbital anatomy. AJNR Am J Neuroradiol. 1998;19:91-94.
Rootman J., editor. Diseases of the Orbit. Philadelphia: Lippincott; 1998.
Supplementary Data
a. Click here to see labeled and unlabeled image views for this case.
b. Click here to see supplemental images for this case.
Case 10
Demographics/clinical history
The patient is a 25-year-old man with prior history of sinus surgery now presenting
with left orbital pain.
FindingsCoronal T1-weighted (Fig. 1) and T2-weighted (Fig. 2) magnetic resonance imaging
(MRI) demonstrate mild thickening of the left medial rectus, inferior rectus, and
superior oblique extraocular muscles. Contrast-enhanced fat-suppressed coronal
T1-weighted MRI (Fig. 3) shows asymmetric thickening and enhancement of the
left medial rectus and inferior rectus muscles. Trace stranding of the adjacent
retrobulbar fat also is noted.
Figure 1 Coronal T1-weighted MRI shows mild thickening of left medial rectus,
inferior rectus, and superior oblique muscles.
Figure 2 Coronal T2-weighted MRI shows mild thickening of extraocular muscles
as seen on T1-weighted MRI (see Fig. 1).
Figure 3 Contrast-enhanced fat-suppressed coronal T1-weighted MRI shows
asymmetric thickening and enhancement of left medial rectus and inferior rectus
muscles. Trace stranding of adjacent retrobulbar fat also is noted.Discussion
Definition/Background
Orbital pseudotumor is an idiopathic in) ammatory syndrome characterized by a
nongranulomatous in) ammatory process involving the orbit, with no known local
or systemic causes. It is a diagnosis of exclusion based on the history, clinical
course of the disease, response to steroid therapy, laboratory tests, and, in a few
cases, biopsy. It is the second most common ophthalmologic disease (after Graves
disease) and accounts for approximately 6% of all orbital disorders. Depending on
the extent and location of in) ammation, pseudotumors have been classi, ed as
acute and subacute idiopathic anterior orbital in) ammation, acute and subacute
di#use orbital in) ammation, acute and subacute idiopathic myositic orbital
in) ammation, acute and subacute idiopathic apical orbital in) ammation,
idiopathic dacryoadenitis, and perineuritis. Some investigators consider
TolosaHunt syndrome (painful external ophthalmoplegia) as a pseudotumor variant.
Characteristic Clinical Features
Typical presenting features include acute onset of orbital pain, restricted eye
movement, diplopia, proptosis, and impaired vision.
Characteristic Radiologic Findings
The imaging findings vary depending on the type of pseudotumor.
Anterior orbital inflammation: Computed tomography (CT) and MRI show
thickening and enhancement of the uveal-scleral rim.
Diffuse orbital pseudotumor: This type may be focal, restricted to the intraconal
or extraconal compartment, or may be diffuse and may involve both
compartments. CT and MRI show bulky masses that can exhibit enhancement, but
do not typically distort or cause destruction of the orbital bony walls.
Orbital myositis: CT and MRI show thickening and enhancement of the involved
muscles. There may be stranding of the adjacent fat.
Apical orbital inflammation: CT and MRI findings include an infiltrative process
seen at the orbital apex, which is identified on imaging as replacement of apical
orbital fat with ill-defined inflammatory soft tissue.
Dacryoadenitis: This is identified by inflammatory change in the region of the
lacrimal gland.
Perineuritis: MRI is more sensitive than CT for evaluation of perineuritis.
Thickening and enhancement of the optic nerve may be seen. Tolosa-Hunt syndrome: This syndrome, or painful external ophthalmoplegia, is
characterized by the presence of abnormal enhancing soft tissue seen in the region
of the cavernous sinus or the superior orbital fissure.
Differential Diagnosis
Anterior orbital inflammation: cellulitis, hemorrhage, leukemia
Diffuse orbital pseudotumor: lymphoma, metastasis, hemangioma
Orbital myositis: Graves disease, metastasis
Apical orbital inflammation: lymphoma, sarcoidosis, Wegener granulomatosis
Dacryoadenitis: viral and bacterial dacryoadenitis, sarcoidosis, Sjögren disease,
lymphoma
Perineuritis: optic nerve glioma, meningioma, optic neuritis
Discussion
It is di. cult to distinguish these di#erent clinical entities based on imaging studies.
Clinical presentation and laboratory tests are helpful.
Diagnosis
The diagnosis is “orbital pseudotumor.”
Suggested Readings
Mafee M.F. Orbit: Embryology, anatomy and pathology. In: Som P.M., Curtin H.D.,
editors. Head and Neck Imaging. 4th ed. St. Louis: Mosby; 2003:529-655.
Mafee M.F., Putterman A., Valvassori G.E., et al. Orbital space-occupying lesions: Role
of CT and MRI, an analysis of 145 cases. Radiol Clin North Am. 1987;25:529-559.
Sobel D.F., Mills C., Char D., et al. NMR of the normal and pathologic eye and orbit.
AJNR Am J Neuroradiol. 1984;5:345-350.
Case 11
Demographics/clinical history
The patient is a 23-year-old man with left-sided proptosis.
FindingsAxial T1-weighted magnetic resonance imaging (MRI) (Fig. 1) shows an ill-de, ned
isointense to hypointense mass lesion lateral to the left ocular globe. Left-sided
proptosis with heterogeneity is seen within the retrobulbar compartment and
thickened left medial rectus. Axial T2-weighted MRI (Fig. 2) shows that the mass
lesion lateral to the left ocular globe consists of multiple ovoid to serpiginous
lesions that exhibit peripheral hyperintensity surrounding a smaller central core of
hypointensity. Similar lesions are seen in the retrobulbar compartment of the left
orbit. Contrast-enhanced fat-suppressed axial, T1-weighted MRI (Fig. 3) at a
corresponding level shows heterogeneous enhancement of the mass lesion lateral to
the left ocular globe and within the retrobulbar compartment and heterogeneous
enhancement of the left medial rectus. Curvilinear, enhancing soft tissue seen along
the posterior wall of the left ocular globe may represent a scleral or choroidal
neurofibroma.
Figure 1 Axial T1-weighted MRI shows ill-de, ned isointense to hypointense mass
lesion (arrow) lateral to left ocular globe. There is left-sided proptosis, with
heterogeneity seen within retrobulbar compartment, and thickened, left medial
rectus.
Figure 2 Axial T2-weighted MRI shows mass lesion lateral to left ocular globe that
consists of multiple, ovoid to serpiginous lesions (arrow) that exhibit peripheral
hyperintensity surrounding a smaller central core of hypointensity. Similar lesions
are seen in retrobulbar compartment of left orbit.Figure 3 Contrast-enhanced fat-suppressed axial T1-weighted MRI at
corresponding level shows heterogeneous enhancement of mass lesion lateral to left
ocular globe (arrow) and within retrobulbar compartment. Heterogeneous
enhancement of left medial rectus can be seen. Curvilinear, enhancing soft tissue
seen along posterior wall of left ocular globe (arrowhead) may represent scleral or
choroidal neurofibroma.
Discussion
Definition/Background
There are four patterns of neuro, bromas: plexiform, di#use, circumscribed, and
postamputation neuromas. Plexiform neuro, bromas involve most fascicles in a
segment of a peripheral nerve, with most such tumors located within the lateral
third of the eyelid, resulting in a “bag of worms” feel on palpation. Their presence
is virtually diagnostic of neuro, bromatosis type 1 (i.e., von Recklinghausen
disease). Di#use neuro, bromas involve the lid, retrobulbar fat, and extraocular
muscles, and they are less commonly associated with von Recklinghausen disease.
Circumscribed neuro, bromas manifest as localized, slow-growing tumors, which
can cause displacement of the globe.
Characteristic Clinical Features
Orbital swelling, exophthalmos, and ptosis with or without diplopia are common
presenting features of plexiform or di#use neuro, bromatosis. Histologically,
neuro, bromas consist of tortuous masses of expanded nerve branches that are cut
in various planes, with scant, haphazard arrangement of spindle cells in a loose
collagen matrix. Hypercellularity, cellular pleomorphism, and mitosis indicate
malignant transformation, which can occur in 2% to 15% of cases.
Characteristic Radiologic Findings
The extent of plexiform and di#use neuro, bromas can be best assessed with MRI.
The secondary osseous, mostly pressure deformities produced by the sometimes
very large lesions are better assessed with computed tomography (CT). The
plexiform and di#use neuro, bromas appear as ill-de, ned, isointense tohypointense mass lesions on T1-weighted MRI. These lesions appear predominantly
hyperintense on T2-weighted MRI; the hyperintense signal is produced by the
myxoid regions of the tumor, and the scarce hypointense signal sometimes seen
centrally within the lesion is produced by the cellular components of the tumor.
Variable contrast enhancement is seen.
Diagnosis
The diagnosis is “diffuse neurofibromatosis.”
Suggested Reading
Carroll G.S., Haik B.G., Fleming J.C., et al. Peripheral nerve tumors of the orbit. Radiol
Clin North Am. 1999;37:195-202.
Supplementary Data
a. Click here to see labeled and unlabeled image views for this case.
Case 12
Demographics/clinical history
The patient is a 10-year-old boy with painless proptosis.
Findings
Non–contrast-enhanced axial computed tomography (CT) scan (Fig. 1) shows
proptosis with enlarged optic nerves bilaterally. Kinking of the intraorbital segment
of both optic nerves also is noted. Non–contrast-enhanced coronal CT scan (Fig. 2)
shows enlarged optic nerves. In a di#erent patient, known to have
neuro, bromatosis 1 (NF1), axial T2-weighted magnetic resonance imaging (MRI)
(Fig. 3) shows enlarged intracranial segments of the optic nerves extending into the
chiasm. Also noted is a dysplastic right wing of sphenoid with right-sided proptosis.
Contrast-enhanced fat-suppressed coronal T1-weighted MRI (Fig. 4) shows mildly
enhancing enlarged optic chiasm.Figure 1 Non–contrast-enhanced axial CT scan shows proptosis with enlarged
bilateral optic nerves. Kinking of intraorbital segment of both optic nerves also is
noted.
Figure 2 Non–contrast-enhanced coronal CT scan shows enlarged optic nerves.
Figure 3 In a di#erent patient with known NF-1, axial T2-weighted MRI shows
enlarged intracranial segments of optic nerves extending into chiasm. A dysplastic
right wing of sphenoid with right-sided proptosis also is noted.Figure 4 Contrast-enhanced fat-suppressed coronal T1-weighted MRI in patient in
Fig. 3 shows mildly enhancing enlarged optic chiasm.
Discussion
Definition/Background
Optic nerve glioma is the most common primary neoplasm of the optic nerve. It
represents about 4% of all orbital tumors, 4% of all intracranial gliomas, and 2% of
all intracranial tumors. It typically is seen in the , rst decade of life. Approximately
15% of patients with optic nerve gliomas have , ndings of NF1 at the time of the
diagnosis. Conversely, approximately 25% of children with NF1 have optic nerve
glioma. Bilateral optic nerve gliomas are virtually pathognomonic of NF1.
Involvement of optic chiasm coexistent with gliomas of both optic nerves is more
common than involvement of a single optic nerve. Involvement of the optic tracts,
lateral geniculate body, and optic radiations is occasionally seen.
Characteristic Clinical Features
Painless proptosis is the most common presenting complaint. Reduced visual acuity
is noted in the latter stages of the disease. Lesions involving the optic chiasm and
the hypothalamic region can cause compression of the third ventricle, resulting in
hydrocephalus and associated symptoms. Typically, optic nerve glioma has been
identi, ed as a low-grade glioma. The more aggressive malignant variety is rare, is
seen in adults, and is usually fatal despite treatment. Development of optic nerve
gliomas occurs in stages, from generalized hyperplasia of glial cells in the nerve to
complete disorganization, with loss of neural landmarks in the nerve and nerve
sheath.
Characteristic Radiologic Findings
MRI is better than CT to show the entire extent of the glioma. It is mandatory to
evaluate the entire optic pathway if there is a suspicion for optic nerve gliomabecause retrochiasmatic involvement can occur. CT shows di#use, fusiform
enlargement of the optic nerve. This di#use enlargement results in buckling of the
nerve. Widening of the optic canal is seen if the tumor extends posteriorly into the
intracranial compartment. Variable enhancement is noted on contrast-enhanced
studies. On MRI, typically optic nerve glioma is seen as a di#use, fusiform
enlargement of the optic nerve. The lesion characteristically appears isointense to
cortex on T1-weighted MRI, appears hyperintense to cortex on T2-weighted MRI,
and shows variable enhancement. Heterogeneity seen within the tumor re) ects
cystic changes. A reactive meningeal hyperplasia may be incited, making optic
nerve glioma difficult to distinguish from a perioptic meningioma.
Differential Diagnosis
Perioptic meningioma
Optic neuritis
Discussion
The presence of stippled calci, cation, reactive hyperostosis of the adjacent bone,
and tram-track enhancement pattern distinguishes perioptic meningioma from
optic nerve glioma. In the acute stage, mild enlargement and enhancement of the
optic nerve in optic neuritis can resemble optic nerve glioma. Other intracranial
, ndings of demyelination, including presence of Dawson , ngers, and involvement
of the callososeptal interface can help distinguish optic neuritis from optic nerve
glioma.
Diagnosis
The diagnosis is “optic nerve glioma.”
Suggested Readings
Azar-Kia B., Naheedy M.H., Elias D.A., et al. Optic nerve tumors: Role of magnetic
resonance imaging and computer tomography. Radiol Clin North Am.
1987;25:561581.
Listernick R., Charrow J., Greenwald M.J., et al. Optic gliomas in children with
neurofibromatosis type 1. J Pediatr. 1989;114:788-792.
Mafee M.F., Putterman A., Valvassori G.E., et al. Orbital space occupying lesion: Role
of computer tomography and magnetic resonance imaging. Radiol Clin North Am.
1987;25:529-559.
Supplementary Dataa. Click here to see supplemental images for this case.
Case 13
Demographics/clinical history
The patient is a 42-year-old man with progressive right-sided visual loss.
Findings
Axial T1-weighted magnetic resonance imaging (Fig. 1) and axial T2-weighted MRI
(Fig. 2) show tubular thickening of the right optic nerve. Contrast-enhanced
fatsuppressed axial T1-weighted MRI (Fig. 3) shows thickened, enhancing optic nerve
sheath around an attenuated optic nerve, resulting in a “tram-track” enhancement
pattern. Contrast-enhanced fat-suppressed coronal T1-weighted MRI (Fig. 4) shows
thickened optic nerve sheath encircling the optic nerve resulting in the “bull’s-eye”
appearance.
Figure 1 Axial T1-weighted MRI shows thickened right optic nerve.
Figure 2 Axial T2-weighted MRI shows tubular thickening of the right optic nerve.Hyperintense signal seen centrally is likely to represent edema or myelomalacia of
the optic nerve, surrounded by isointense to hypointense signal more peripherally,
likely representing the thickened optic nerve sheath.
Figure 3 Contrast-enhanced fat-suppressed axial T1-weighted MRI shows
thickened, enhancing optic nerve sheath around attenuated optic nerve resulting in
“tram-track” enhancement pattern.
Figure 4 Contrast-enhanced fat-suppressed coronal T1-weighted MRI shows
thickened optic nerve sheath encircling optic nerve, resulting in “bull’s-eye”
appearance.
Discussion
Definition/Background
Optic nerve sheath meningiomas (ONSM) are rare, benign, primary intraorbital
meningiomas that arise from the arachnoid cap cells within the optic nerve sheath.
Secondary orbital meningiomas represent the intraorbital extension of neoplasm
from sites immediately adjacent to the orbit and account for 90% of orbital
meningiomas. ONSM are typically seen in middle-aged patients. Meningiomas
involve the orbit in 0.4% to 1.3% of cases, and 3% of orbital neoplasms aremeningiomas.
Characteristic Clinical Features
Painless, chronic progressive visual loss, which may be accompanied by proptosis,
is a classic presenting feature of ONSM. On examination, the presence of associated
optic disk atrophy and of retinociliary shunt vessels (so-called Hoyt-Spencer triad)
is diagnostic of ONSM.
Characteristic Radiologic Findings
High-resolution contrast-enhanced computed tomography (CT) and
contrastenhanced fat-suppressed MRI should be used to evaluate ONSM. Three patterns of
growth of ONSM have been described: tubular, fusiform, and globular. The typical
appearance of ONSM is of an enhancing mass surrounding an attenuated optic
nerve. This produces the “bull’s eye” appearance on coronal contrast-enhanced
images and the “tram-track” sign on contrast-enhanced axial images.
Less Common Radiologic Manifestations
Occasionally, linear, di#use, or patchy calci, cation along ONSM can be seen on
CT. Rarely, widening of the optic canal, bony hyperostosis, and pneumosinus
dilatans are seen. Bilateral ONSM are associated with multiple meningiomas.
Multiple meningiomas are associated with neuro, bromatosis (NF) 2. ONSM have
rarely been associated with radiation therapy.
Differential Diagnosis
Optic neuritis
Optic nerve glioma
Neurosarcoidosis
Discussion
The nerve itself shows enhancement in optic neuritis. Associated additional
demyelinating lesions may be seen in the brain or spinal cord or both.
Occasionally, in the absence of demyelinating lesions in the brain or spinal cord,
distinction between optic neuritis and ONSM can be di. cult. A history of slowly
progressive visual loss despite treatment and in the absence of con, rmatory
indicators of demyelination should raise a red ) ag for ONSM. Optic nerve glioma
shows a fusiform enlargement of the optic nerve with or without enhancement. A
normal-appearing dura is seen. Occasionally, kinking of the optic nerve may be
seen. Optic nerve glioma is associated with NF1, and evaluation for other NF1
lesions should be performed. It can be di. cult sometimes to distinguishneurosarcoidosis from ONSM. The presence of abnormal leptomeningeal
enhancement that can be seen in neurosarcoidosis should help distinguish the two
entities.
Diagnosis
The diagnosis is “optic nerve sheath meningioma.”
Suggested Readings
Jackson A., Patankar T., Laitt R.D. Intracanalicular optic nerve meningioma: A serious
diagnostic pitfall. AJNR Am J Neuroradiol. 2003;24:1167-1170.
Mafee M.F., Goodwin J., Dorodi S. Optic nerve sheath meningiomas: Role of MR
imaging. Radiol Clin North Am. 1999;37:37-58.
Ortiz O., Schochet S.S., Kotzan J.M., et al. Radiologic-pathologic correlation:
Meningioma of the optic nerve sheath. AJNR Am J Neuroradiol. 1996;17:901-906.
Case 14
Demographics/clinical history
The patient is a 5-month-old girl with right-sided ptosis and a nontender, growing
red area along the superior quadrant of the orbit.
Findings
Coronal T1-weighted magnetic resonance imaging (MRI) (Fig. 1), T2-weighted MRI
(Fig. 2), and contrast-enhanced fat-suppressed coronal T1-weighted MRI (Fig. 3)
show a well-de, ned, enhancing lesion in the extraconal compartment of the right
orbit. Flow voids within the lesion are also seen.Figure 1 Coronal T1-weighted MRI shows well-de, ned lesion appearing
isointense to brain parenchyma in extraconal compartment of right orbit.
Figure 2 Lesion appears mildly hyperintense on coronal T2-weighted MRI. Flow
voids are seen within lesion.Figure 3 Intense enhancement is noted on fat-suppressed contrast-enhanced
coronal T1-weighted MRI.
Discussion
Definition/Background
Capillary hemangiomas are one of the most common benign orbital masses of
infancy. They are believed to represent hamartomatous proliferation of vascular
endothelial cells. Typically absent at birth, they exhibit rapid growth during
infancy, with spontaneous involution later in life. This is in contrast to other
childhood vascular malformations, such as lymphangiomas and arteriovenous
malformations, which are present at birth and exhibit a slow growth pattern with
persistence into adult life.
Characteristic Clinical Features
Typically, parents notice a rapidly growing red area in the periorbital region. The
lesion characteristically blanches on pressure. Depending on the location of the
hemangioma, decreased visual acuity can be noted.
Characteristic Radiologic Findings
Computed tomography (CT) and MRI can be used to evaluate capillary
hemangiomas. MRI with its inherent soft tissue resolution helps evaluate this lesion
better. This lesion is typically seen in the extraconal compartment, especially in the
superior nasal quadrant. CT shows capillary hemangioma as a relatively
wellde, ned lesion which demonstrates intense homogeneous enhancement. On MRI,
capillary hemangioma is identi, ed as a lobulated, irregularly marginated lesionthat appears hypointense to slightly hyperintense to the brain on T1-weighted MRI,
hyperintense on T2-weighted MRI, and exhibits intense homogeneous
enhancement. Small, serpentine flow voids are frequently seen within this lesion.
Less Common Radiologic Manifestations
CT angiography or digital subtraction angiography can sometimes show the arterial
feeders, which are from either the external carotid artery or the internal carotid
artery. Occasionally, these lesions can extend into the intracranial compartment via
the superior orbital fissure, optic canal, or orbital roof.
Differential Diagnosis
Dermoid cysts
Lymphangioma
Rhabdomyosarcoma
Discussion
Dermoids typically are more cystic in appearance and do not exhibit the intense
enhancement pattern seen in capillary hemangiomas. Lymphangiomas are typically
multicompartmental, appear more cystic, and do not show the intense
enhancement patterns seen in capillary hemangiomas. Rhabdomyosarcomas are
aggressive, destructive lesions that typically cause adjacent bone destruction.
Diagnosis
The diagnosis is “capillary hemangioma of the orbit.”
Suggested Readings
Bilaniuk L.T. Orbital vascular lesions: Role of imaging. Radiol Clin North Am.
1999;37:169-182.
Kavanagh E.C., Heran M.K., Peleg A., Rootmann J. Imaging of the natural history of
an orbital capillary hemangioma. Orbit. 2006;25:69-72.
Smoker W.R., Gentry L.R., Yee N.K., et al. Vascular lesions of the orbit: More than
meets the eye. RadioGraphics. 2008;28:185-204.
Case 15
Demographics/clinical historyThe patient is a 32-year-old man with mild right ocular discomfort.
Findings
Axial T1-weighted magnetic resonance imaging (MRI) (Fig. 1) shows a well-defined
hypointense to isointense lesion in the retrobulbar compartment of the right orbit.
Axial T2-weighted MRI (Fig. 2) shows the lesion to be mildly hyperintense and
adjacent to the right lateral rectus muscle. Contrast-enhanced coronal T1-weighted
MRI (Fig. 3) shows moderate enhancement.
Figure 1 Axial T1-weighted MRI shows well-de, ned hypointense to isointense
lesion in retrobulbar compartment of right orbit.
Figure 2 Axial T2-weighted MRI shows lesion to be mildly hyperintense and
adjacent to right lateral rectus muscle.Figure 3 Contrast-enhanced coronal T1-weighted MRI shows moderate
enhancement.
Discussion
Definition/Background
Cavernous hemangioma is the most common orbital vascular tumor; it is typically
seen in middle-aged adults. Most often unilateral, these lesions are classically
located in the retrobulbar compartment and exhibit slow, progressive enlargement.
They are devoid of any prominent arterial supply and possess a distinct , brous
pseudocapsule, enabling easy excision.
Characteristic Clinical Features
Mild ocular fullness or discomfort is the primary complaint. If the lesion encroaches
on the optic nerve or the globe, the patient may complain of change in visual
acuity. Extraocular muscle impingement can cause extraocular muscle dysfunction
and diplopia.
Characteristic Radiologic Findings
Computed tomography (CT) and MRI can be used to evaluate cavernous angiomas.
CT shows a well-de, ned, ovoid or rounded, homogeneous soft tissue density mass
with variable contrast enhancement. MRI typically shows a well-de, ned, ovoid or
rounded, homogeneous soft tissue mass hypointense on T1-weighted MRI,
hyperintense on T2-weighted MRI, and showing variable contrast enhancement.
Less Common Radiologic Manifestations
Calci, cation is rarely seen. If seen, the diagnosis of sclerosing hemangiomas should
be entertained. Late pooling of contrast material is rarely seen.
Differential Diagnosis Meningioma
Schwannoma
Lymphoma
Hemangiopericytoma
Discussion
Meningioma typically is seen in relation to the optic nerve sheath complex and can
show stippled calci, cation and occasional hyperostosis. Most meningiomas appear
hyperdense on non–contrast-enhanced CT scans. “Tram-track” enhancement is
highly suggestive of meningioma. The optic nerve has no Schwann cells. Orbital
schwannomas arise from peripheral nerve , bers of cranial nerves III, IV, V, VI, and
VII and autonomic nerves. Most such schwannomas are well-de, ned, lobulated soft
tissue lesions hypointense on T1-weighted MRI and hyperintense on T2-weighted
MRI, and showing moderate to marked enhancement. Bony remodeling is seen.
Orbital lymphoma can appear as a well-de, ned soft tissue density mass, typically
hyperdense on non–contrast-enhanced CT scan and hypointense on T1-weighted
MRI and T2-weighted MRI with mild to moderate enhancement.
Hemangiopericytomas are rare lesions that have an irregular, lobulated contour
and intense early enhancement after contrast agent administration. Erosion of the
underlying bone can be seen.
Diagnosis
The diagnosis is “cavernous hemangioma of the orbit.”
Suggested Readings
Ansari S.A., Mafee M.F. Orbital cavernous hemangioma: Role of imaging.
Neuroimaging Clin North Am. 2005;15:137-158.
Bilanuik L.T. Orbital vascular lesions: Role of imaging. Radiol Clin North Am.
1999;37:169-183.
Daniels D.L., Yu S., Pech P., et al. Computed tomography and magnetic resonance
imaging of the orbital apex. Radiol Clin North Am. 1987;25:803-817.
Mafee M.F. Imaging of the orbit. In: Valvassori G.E., Mafee M.F., Carter B., editors.
Imaging of the Head and Neck. Stuttgart: Georg Thieme; 1995:248-327.
Case 16
Demographics/clinical historyThe patient is a 3-year-old boy with leukocoria.
Findings
Axial T2-weighted magnetic resonance imaging (MRI) (Fig. 1) shows a
subcentimeter-sized hypointense lesion adjacent to the left optic disk. A suprasellar
mass is also noted. Sagittal T1-weighted MRI (Fig. 2) shows a sellar/suprasellar
mass. A di#usion-weighted image (Fig. 3) shows small focus of restricted di#usion
adjacent to the left optic disk. Also noted is restricted di#usion in the suprasellar
region. In a di#erent patient, an axial computed tomography (CT) scan (Fig. 4)
shows a calcified mass in the posterior right ocular globe.
Figure 1 Axial T2-weighted MRI shows subcentimeter-sized hypointense lesion
(arrowhead) adjacent to left optic disk. Suprasellar mass (star) also is noted.
Figure 2 Sagittal T1-weighted MRI shows sellar/suprasellar mass.Figure 3 Di#usion-weighted image shows small focus of restricted di#usion
(arrowhead) adjacent to left optic disk. Also noted is restricted di#usion in
suprasellar region.
(Courtesy of Aroostook Vossough, MD, Ph.D, Children’s Hospital of Philadelphia, PA)
Figure 4 In a di#erent patient, axial CT scan shows calci, ed mass in posterior
right ocular globe.
Discussion
Definition/Background
Retinoblastoma is the most common primary ocular malignancy of childhood; it is
seen typically in patients about 2 years of age. Unilateral and bilateral
retinoblastomas have been reported. Occurrence of ectopic retinoblastoma in the
pineal or parasellar region has been reported as trilateral retinoblastoma.
Tetralateral retinoblastoma is extremely rare and refers to the syndrome of bilateral
retinoblastoma with a solitary midline intracranial tumor in the pineal gland,
suprasellar region, or parasellar region (i.e., two distinct midline intracranial
neuroblastic tumors associated with bilateral retinoblastomas). Rare di#use
in, ltrative retinoblastoma poses a diagnostic challenge because of the unusual
morphologic appearance. These tumors do not exhibit any calci, cation and appearas diffuse retinal thickening without the presence of a discrete mass.
Characteristic Clinical Features
Leukocoria is the most common presenting sign. Strabismus (squint), which occurs
as a result of visual loss, is the second most common presentation.
Characteristic Radiologic Findings
CT is the initial imaging study of choice. MRI should be obtained to evaluate the
extent of the lesion. Presence of calci, cation within the globe, typically adjacent to
the optic disk in children younger than 3 years, is highly suggestive of
retinoblastoma. An associated enhancing soft tissue mass can also be seen. On MRI,
the lesion appears hyperintense to the normal vitreous on T1-weighted MRI,
hypointense on T2-weighted MRI and shows contrast enhancement. Restricted
di#usion can be seen on di#usion-weighted imaging (DWI). It should be noted that
lesions less than 3 to 4 mm in height can be missed on MRI. In addition to
evaluation of the globe for retinoblastoma, imaging should be extended to the
brain to evaluate for trilateral and tetralateral retinoblastomas.
Differential Diagnosis
Persistent hyperplastic primary vitreous
Coats disease
Larval endophthalmitis
Retinal astrocytic hamartomas (giant drusen)
Discussion
Persistent hyperplastic primary vitreous is a congenital lesion resulting from
persistence of fetal vasculature. Absence of calci, cation and presence of
microphthalmia is suggestive of this lesion. Coats disease refers to unilateral retinal
telangiectasia. It is seen in an older age group. Lack of calci, cation and lack of
enhancement within the subretinal space distinguish Coats disease from
retinoblastoma. Larval endophthalmitis is a chronic granulomatous in) ammatory
response to Toxocara larva. Patients are slightly older (>5 years) with a history of
contact with dogs. Serologic titers are helpful. With retinal astrocytic hamartomas,
the presence of calci, cation makes it di. cult to di#erentiate these lesions from
retinoblastoma. Findings of associated tuberous sclerosis or neuro, bromatosis 1
should suggest the diagnosis of retinal astrocytic hamartomas. It should be noted
that presence of calci, cation adjacent to the optic disk in a pediatric patient (2
years of age) should always raise a red ) ag for retinoblastoma. Also, bilateral softtissue enhancing optic disk lesions should be considered retinoblastomas until
proven otherwise.
Diagnosis
The diagnosis is “retinoblastoma.”
Suggested Readings
Chung E.M., Specht C.S., Schroeder J.W. From the archives of AFIP. Pediatric orbit
tumors and tumorlike lesions: Neuroepithelial lesions of the ocular globe and optic
nerve. RadioGraphics. 2007;27:1159-1186.
Epstein J.A., Shields C.L., Shields J.A. Trends in the management of retinoblastoma:
Evaluation of 1,196 consecutive eyes during 1974 to 2001. J Pediatr Ophthalmol
Strabismus. 2003;40:196-203.
Mafee M.M. The eye. In: Som P.M., Curtin H.D., editors. Head and Neck Imaging. 4th
ed. St. Louis: Mosby; 2003:441-527.
Supplementary Data
a. Click here to see labeled and unlabeled image views for this case.
Case 17
Demographics/clinical history
The patient is a 52-year-old man with decreased visual acuity.
Findings
Axial T1-weighted (Fig. 1), axial T2-weighted (Fig. 2), and contrast-enhanced axial
T1-weighted (Fig. 3) magnetic resonance imaging (MRI) studies show a relatively
well-de, ned, left choroidal mass lesion. The lesion appears minimally hyperintense
on T1-weighted MRI and hypointense on T2-weighted MRI and shows moderate to
significant contrast enhancement.Figure 1 Axial T1-weighted MRI shows well-de, ned, minimally hyperintense,
leftchoroidal mass (arrow).
Figure 2 The lesion appears hypointense on axial T2-weighted MRI.
Figure 3 Moderate to intense enhancement of lesion is seen after administration
of contrast agent.
(Courtesy of Gul Moonis, MD, Beth Israel Deaconness, Medical Center, MA)
DiscussionDefinition/Background
Uveal melanoma is the most common primary ocular neoplasm in adults. Almost
always unilateral, these neoplasms are often seen in middle-aged white men. The
tumor arises from malignant transformation of melanocytes in the uveal tract. Most
often, uveal melanomas are seen arising from the choroid; less often, from the
ciliary body; and least often, from the iris.
Characteristic Clinical Features
Uveal melanomas can remain asymptomatic for a long time. Blurred vision and
decreased visual acuity have occasionally been reported. Often, these neoplasms
are identified on ophthalmoscopic examination.
Characteristic Radiologic Findings
MRI is the imaging study of choice for evaluation of uveal melanomas. Typically, a
well-de, ned, sharply marginated choroidal mass lesion hyperintense on
T1weighted MRI and moderately hypointense on T2-weighted MRI is seen. The lesion
shows enhancement after administration of contrast agent. Associated retinal
detachment can be seen. Computed tomography (CT) scan typically shows a
wellde, ned, sharply marginated choroidal mass. Increasing tumoral pigmentation (best
assessed on T1-weighted MRI), increasing size, in, ltration of the ciliary body, and
retinal detachment are considered to be poor prognostic factors.
Less Common Radiologic Manifestations
In cases of amelanotic melanomas, the characteristic hyperintense signal intensity
on T1-weighted MRI is not seen. At such times, the lesion can appear isointense to
hypointense on T1-weighted MRI. Also, a heterogeneous signal on T1-weighted
MRI can be seen in patients with hemorrhagic lesions.
Differential Diagnosis
Metastatic lesions
Choroidal hemangioma
Choroidal cyst
Nerve sheath tumor of uvea
Lymphoma
Leiomyoma
DiscussionThe presence of hyperintense signal on T1-weighted MRI is highly suggestive of
uveal melanomas. Otherwise, based on imaging alone, it can be di. cult to
distinguish these different clinical entities.
Diagnosis
The diagnosis is “malignant choroidal (uveal) melanoma.”
Suggested Readings
Augsburger J.J., Gamel J.W. Clinical prognostic factors in patients with posterior
uveal malignant melanoma. Cancer. 1990;66:1596-1600.
Lemke A.J., Hosten N., Bornfeld N., et al. Uveal melanoma: Correlation of
histopathologic and radiologic imaging using thin-section MR imaging with a
surface coil. Radiology. 1999;210:775-783.
Mafee M.F., Peyman G.A. Retinal and choroidal detachments: Role of magnetic
resonance imaging and computed tomography. Radiol Clin North Am.
1987;25:487507.
McLean M.J., Foster W.D., Zimmerman L.E. Prognostic factors in small malignant
melanomas of choroid and ciliary body. Arch Ophthalmol. 1977;95:48-58.
Supplementary Data
a. Click here to see labeled and unlabeled image views for this case.
Case 18
Demographics/clinical history
The patient is a 43-year-old man with lung carcinoid tumor, with restriction of
extraocular movements of the left orbit.
Findings
Coronal T1-weighted magnetic resonance imaging (MRI) (Fig. 1) shows a
wellde, ned mass lesion along the medial rectus of the left orbit. Coronal T2-weighted
MRI (Fig. 2) shows the lesion to be hypointense to the extraocular muscles.
Contrast-enhanced fat-suppressed coronal T1-weighted MRI (Fig. 3) shows
nearhomogeneous enhancement of the lesion.Figure 1 Coronal T1-weighted MRI shows well-de, ned mass lesion along medial
rectus of left orbit.
Figure 2 Coronal T2-weighted MRI shows lesion to be hypointense to extraocular
muscles.
Figure 3 Contrast-enhanced fat-suppressed coronal T1-weighted MRI shows
nearhomogeneous enhancement of lesion.
Discussion
Definition/Background
Secondary orbital tumors can occur from malignant tumors invading the orbit from
adjacent structures, such as the paranasal sinuses, skin, and subcutaneous tissue, or
secondary to metastasis. Metastatic lesions to the orbit most commonly result from
breast carcinoma in women and carcinoma of the lung, kidney, or prostate in men.In children, metastasis is seen from neuroblastoma, Ewing sarcoma, and Wilms
tumor.
Characteristic Clinical Features
Clinical presentation varies depending on the underlying etiology and extent of
involvement.
Characteristic Radiologic Findings
The imaging appearance varies depending on the underlying etiology and extent of
involvement.
Differential Diagnosis
Lymphoma
Hemangioma
Pseudotumor
Schwannoma
Discussion
Based on imaging alone, it can be di. cult to distinguish these di#erent clinical
entities. However, presence of a mass within the orbit in a patient with known
primary tumor should be suggestive of metastasis.
Diagnosis
The diagnosis is “metastatic carcinoid tumor to the orbit.”
Suggested Readings
Ahmad S.M., Esmaeli B. Metastatic tumors of the orbit and ocular adnexa. Curr Opin
Ophthalmol. 2007;18:405-413.
Braffman B.H., Bilaniuk L.T., Eagle R.C.Jr, et al. MR imaging of a carcinoid tumor
metastatic to the orbit. J Comput Assist Tomogr. 1987;11:891-894.
Mafee M.F. Orbit: Embryology, anatomy, and pathology. In: Som P.M., Curtin H.D.,
editors. Imaging of the Head and Neck. 4th ed. St. Louis: Mosby; 2003:529-654.
Case 19
Demographics/clinical historyThe patient is a 42-year-old woman with a right orbital mass.
Findings
Non–contrast-enhanced axial computed tomography (CT) scan (Fig. 1) shows a
predominantly preseptal right extraocular mass. Scalloping of the adjacent osseous
structures is seen. No obvious bony destruction is noted. This mass is also seen to
extend into the postseptal (retrobulbar) compartment. Axial T1-weighted (Fig. 2),
axial T2-weighted (Fig. 3), and contrast-enhanced fat-suppressed axial
T1weighted (Fig. 4) magnetic resonance imaging (MRI) studies show the large,
irregular-marginated, right orbital mass. Thickening and enhancement of the
extraocular muscles suggests contiguous involvement versus secondary myositis.
In) ammatory mucosal thickening is seen to involve the right ethmoid sinuses.
There is no contiguous extension of this mass into the adjacent paranasal sinuses.
Figure 1 Non–contrast-enhanced axial CT scan shows large, predominantly
preseptal right extraocular mass. Scalloping of the adjacent osseous structures is
seen. No obvious bony destruction is noted. This mass is also seen to extend into the
postseptal (retrobulbar) compartment.
Figure 2 Axial T1-weighted MRI shows large, irregular-marginated, right orbital
mass.Figure 3 Axial T2-weighted MRI shows thickening of extraocular muscles
suggestive of contiguous involvement versus secondary myositis. In) ammatory
mucosal thickening is seen to involve right anterior ethmoid sinuses.
Figure 4 Contrast-enhanced fat-suppressed axial T1-weighted MRI shows
nearhomogeneous enhancement of mass.
Discussion
Definition/Background
Sebaceous carcinoma is an uncommon, aggressive tumor. It arises from the
sebaceous glands of the skin. It is especially common in the periocular region
because this area is particularly rich in sebaceous glands. It is most often seen in
middle-aged women.
Characteristic Clinical Features
Presentation is often nonspeci, c. Very often, it is mistaken for a chalazion in the
early stages of the disease. However, loss of cilia should suggest underlying
malignancy. Advanced cases will show an obvious mass lesion.
Characteristic Radiologic FindingsCT and MRI can be used to evaluate for sebaceous gland carcinomas. A
heterogeneously enhancing, locally aggressive mass lesion is seen. Although
aggressive, the lesion tends to scallop and not destroy the adjacent osseous
structures. Lymphadenopathy can be seen. Distant metastasis by the hematogenous
route is seen in advanced cases. Such metastatic sites include lung, liver, bone, and
brain.
Differential Diagnosis
Basal cell carcinoma
Squamous cell carcinoma
Melanoma
Lymphoma
Merkel cell carcinoma
Metastasis
Discussion
There are no speci, c imaging features for any of these lesions. Any of the
abovelisted masslike skin lesions warrants consideration. The pathologist remains the
final arbiter.
Diagnosis
The diagnosis is “extraocular sebaceous carcinoma arising from the upper eyelid.”
Suggested Readings
Briscoe D. Primary sebaceous carcinoma of the lacrimal gland. Br J Ophthalmol.
2001;85:625.
Ray J., Schofield J.B., Shotton J.C., et al. Rapidly invading sebaceous carcinoma of the
external auditory canal. J Laryngol Otol. 1999;113:578-580.
Reina R.S., Parry E. Aggressive extra-ocular sebaceous carcinoma in a 52-year-old
man. Dermatol Surg. 2006;32:1283-1286.
Shields J.A., Demirci H., Marr B.P., et al. Sebaceous carcinoma of the ocular region: A
review. Surv Ophthalmol. 2005;50:103-122.
Case 20Demographics/clinical history
The patient is a 42-year-old man with trauma, infection, and restricted gaze.
Findings
Contrast-enhanced axial computed tomography (CT) scan (Fig. 1) shows a
peripherally enhancing collection seen in the preseptal compartment of the medial
left orbit, suggestive of an abscess. In a di#erent patient with trauma, a coronal CT
scan (Fig. 2) shows a fracture involving the ) oor of the right orbit, suggestive of an
orbital blow-out fracture. The fracture fragments cause entrapment of the inferior
rectus muscle, resulting in restriction of upward gaze. In a di#erent patient with
breast carcinoma and restriction of extraocular movements, a contrast-enhanced
axial CT scan (Fig. 3) shows a retrobulbar soft tissue mass. PET/CT (Fig. 4) in this
18patient shows increased F-) uorodeoxyglucose (FDG) uptake at the site of the
mass. This was subsequently proven to be a case of metastatic scirrhous carcinoma
of the breast.
Figure 1 Contrast-enhanced axial CT scan shows peripherally enhancing
collection in preseptal compartment of medial left orbit, suggestive of an abscess.
Figure 2 In a di#erent patient with trauma, coronal CT scan shows fracture
involving ) oor of the right orbit, suggestive of orbital blow-out fracture. The
fracture fragments caused entrapment of the inferior rectus muscle, resulting in
restriction of upward gaze.Figure 3 In a di#erent patient with breast carcinoma and restriction of
extraocular movements, contrast-enhanced axial CT scan shows retrobulbar soft tissue
mass.
Figure 4 PET/CT in the patient from Fig. 3 shows increased FDG uptake at the
site of the mass. This was subsequently proven to be metastatic scirrhous carcinoma
of the breast.
Discussion
Definition/Background
Ocular motility disorders, also known as strabismus, can be congenital or acquired.
Ocular motility disorders are usually congenital when seen in infancy or childhood,
but acquired forms can occur at any age. Lesions responsible for ocular motility
disorders can result from local globe or extraocular muscle involvement or
involvement of the cranial nerves (III, IV, V, and VI), or from a more central cause.
Occasionally, no definite cause can be established for strabismus.
Characteristic Clinical Features
Depending on the muscles involved, there is restriction of ocular globe movements.
Characteristic Radiologic Findings
Radiologic findings vary depending on the underlying cause.Diagnosis
The diagnosis is “acquired ocular motility disorders.”
Suggested Readings
Kadom N. Pediatric strabismus imaging. Curr Opin Ophthalmol. 2008;19:371-378.
Mafee M.F. Orbit: Embryology, anatomy, and pathology. In: Som M., Curtin H.D.,
editors. Imaging of the Head and Neck. 4th ed. St. Louis: Mosby; 2003:529-654.
Sharpe J.A. Cortical control of eye movements. Curr Opin Neurol. 1998;11:31-38.
Case 21
Demographics/clinical history
The patient is a 35-year-old man with trauma.
Findings
An axial computed tomography (CT) scan (Fig. 1) shows right periorbital soft tissue
hematoma extending into the postseptal compartment along the lateral wall of the
orbit. The lens on the right side is not seen, suggesting disruption of the lens
capsule. At an adjacent level, axial CT scan (Fig. 2) shows a pocket of air in the
right ocular globe, suggestive of intraocular emphysema. A coronal CT scan (Fig. 3)
showed crenated margins of the right globe, suggesting rupture of the right globe.
In a di#erent patient with history of blunt trauma to the left orbit, an axial CT scan
(Fig. 4) shows increased density within the globe, suggesting hemorrhage within
the anterior and the vitreous chamber. The lens is not visualized, suggesting
disruption of the lens capsule. Also noted is hematoma within the adjacent soft
tissues.
Figure 1 Axial CT scan shows right periorbital soft tissue hematoma extending