Doctor, What is Wrong with My Eye? Common and Uncommon Extra-ocular Lesions A Case-Based Tutorial eEdE-111 Jason B. Mueller, M.D.1 Lindell R. Gentry, M.D.2 Deborah L. Reede, M.D.3 Wendy R.K. Smoker, M.D.1 1University of Iowa Hospitals and Clinics, Iowa City, IA; 2University of Wisconsin Hospital and Clinics, Madison, WI; 3SUNY Downstate Medical Center, Brooklyn, NY Financial Disclosure Learning Objectives • Learn the most common extra-ocular lesions of the orbit • Become familiar with important, but less common orbital lesions that must also be considered in the differential diagnosis • Learn the discriminating imaging features of these entities Introduction Case 1 “Eyebrow mass” Diagnosis? 1. Dacryocystocele 2. Dermoid cyst 3. Lacrimal cyst 4. Abscess • Represent ectodermal inclusion cysts. • Often contain primarily lipid, but may also contain fluid and solid tissue, as in this case • Most common location = superolateral orbit • May produce mass effect on intraorbital contents and even cause bone remodeling Case 2 22F with decreased vision OU Diagnosis? 1. Perioptic meningioma 2. Optic neuritis 3. Optic nerve schwannoma 4. Optic pathway glioma (OPG) 2/3 of all optic nerve tumors;3% of orbital tumors OPGs : meningiomas = 4:1 Present with proptosis and decreased visual acuity Typically slow growing; >90% before age 20 Fusiform enlargement of the optic nerve with variable enhancement • CSF is still visible within the ON sheath. There is also posterior extension to the optic chiasm in this case • • • • • Case 2 continued 22F with decreased vision OU Of the following, this patient is most likely to have: 1. Tuberous sclerosis 2. Neurofibromatosis I 3. Neurofibromatosis II 4. Sturge-Weber Syndrome • 10-35% of patients with optic gliomas have NF1 • Conversely, 15% of NF1 patients will have optic pathway gliomas Case 3 Diagnosis? 1. Meningioma 2. Venous varix 3. Cavernous malformation 4. Abscess 44F with painless proptosis • Most common adult intraconal lesion • Erroneously called “cavernous hemangiomas”,--NOT true neoplasm • Present with painless proptosis that slowly progresses. • T1=isointense ; T2=hyperintense +/hypointense fibrous pseudocapsule • Patchy CE on arterial phase, which homogeneously fills in on delayed images T1 pre-contrast Immediate post-contrast T2 One hour delay Cavernous Malformation companion case • Phleboliths are not typical, but helpful when present • Cavernous malformations require no treatment if asymptomatic • Surgical resection is often curative if lesion is causing visual • disturbances or significant mass effect • Pseudocapsule facilitates removal of the lesion T2 Immediate post Delay Courtesy V Runge, MD Case 4 6 month old with “eyelid swelling” Diagnosis?: 1. Venous varix 2. Orbital cellulitis 3. Cavernous malformation 4. Capillary hemangioma • AKA infantile hemangioma-most common orbital vascular TUMOR of infancy • Growth phase (1-2 years); involutional phase (after 2 years); 50% involute by age 5. • Steroid therapy is very effective and indicated for decreased vision/cosmesis. • T1 isointense, T2 hyperintense • Homogeneous enhancement; flow voids may be present Case 5 Positional proptosis Diagnosis? 1. Venous varix 2. Orbital cellulitis 3. Cavernous malformation 4. Capillary hemangioma • Result from dilation of orbital veins secondary to weakness of vessel wall • Most common cause of spontaneous orbital hemorrhage. • May be occult on imaging without provocative maneuvers. The abnormal veins become engorged during Valsalva or prone positioning • Fluid-fluid levels may be present. • MR signal is variable on depending on the age of blood products Supine Prone Case 6 Progressive, painless proptosis Diagnosis? 1. Carotid-cavernous fistula 2. Orbital cellulitis 3. Meningioma 4. Lymphatic malformation • Multilobulated, trans-spatial, enhancing mass composed of abnormal, dilated lymphatic channels • Multiple fluid-fluid levels are characteristic • May hemorrhage rapid increase in size • Observation is the mainstay of treatment; corticosteroids can be used for swelling/pain • Surgical resection difficult; high recurrence rate Case 7 Chemosis, proptosis, and bruit Diagnosis? 1. Carotid-cavernous fistula (CCF) 2. Orbital cellulitis 3. Venous varix 4. Venolymphatic malformation Ans. 1 Carotid-Cavernous Fistula • Congested, hypervascular cavernous sinus • Arterialized flow within the superior ophthalmic vein • CCFs may be direct (trauma or ruptured cavernous ICA aneurysm) or indirect ( AVM or hypervascular tumor draining into the cavernous sinus) • Worrisome signs of CCF include intracranial hemorrhage, cortical venous shunting, and rapid visual loss Carotid-Cavernous Fistula Post-coiling Arterialized superior ophthalmic vein Most CCFs can be treated via an endovascular approach. Case 8 Diabetic, fever, abrupt vision loss OD Diagnosis? 1. Optic neuritis 2. Optic nerve glioma 3. Optic nerve infarction 4. Perioptic meningioma DWI Ans. 3 Optic Nerve Infarction DWI • Note Rt ON diffusion restriction to the chiasm The nerve is also thickened and edematous • Etiology of this patient’s symptoms was invasive fungal sinusitis (in this case mucormycosis), as evidenced by the extensive paranasal sinus disease • Invasion of the ICA and its branches with resulting infarction is a known complication Case 9 Exophthalmos Diagnosis?: 1. Metastases 2. Thyroid associated orbitopathy (TAO) 3. Pseudotumor 4. Sarcoidosis Ans. 2 Thyroid Associated Orbitopathy • Secondary to Grave’s disease • Most common orbital disorder and most common cause of exophthalmos in adults. • Spindle-shaped enlargement and intense enhancement of affected muscles • Distribution of extraocular muscles affected is specific and remembered with the mnemonic “I’M SLO”; inferior, medial, superior, lateral recti, and obliques. • Notice tendon sparing which is characteristic and a key distinguishing feature from pseudotumor. Case 10 Acute, painful proptosis OS Diagnosis?: 1. Metastases 2. Thyroid associated orbitopathy 3. Pseudotumor 4. Sarcoidosis Ans. 3 Pseudotumor • Nongranulomatous idiopathic inflammatory disorder. Myositic (EOM) pattern (this case) is the most common • Second most common orbital disorder after Grave’s disease; Acute, subacute, or chronic • Extraocular muscles become enlarged without a specific predilection, unlike TAO • Also unlike TAO, there is involvement of the muscle tendons • Treated with corticosteroids, to which there is usually a good response Case 11 31F with acute decreased vision and pain OD Diagnosis? 1. Optic neuritis (ON) 2. Optic nerve glioma 3. Optic nerve infarction 4. Perioptic meningioma • Optic neuritis is an idiopathic autoimmune condition characterized by abrupt visual loss and orbital pain • Corticosteroids accelerate initial recovery but do not alter long-term vision recovery • Key imaging features include optic nerve enhancement, mild enlargement, and increased T2SI Case 11 continued 31F with acute decreased vision and pain OD What process is indicated by the yellow arrow? 1. Chronic small vessel ischemia 2. Acute infarction 3. Inactive demyelination 4. Active demyelination • ON is highly associated with multiple sclerosis (MS). • >50% of patients with ON develop MS, especially women • MS plaques are demonstrated on the T2WI • Contrast enhancement demonstrated on the lower image confirms that active demyelination is occurring Case 12 Progressive, painless visual loss Diagnosis? 1. Optic neuritis 2. Optic nerve glioma 3. Optic nerve infarction 4. Perioptic meningioma Ans. 4 Perioptic Meningioma • Typically present with slowly progressive, painless visual loss • Marked T2 hypointensity, a characteristic feature • “Tram track” and circumferential intense, homogeneous enhancement, also key findings. Note normal optic nerve • Calcifications are present in up to 50% of cases often with “tram track” morphology as in bottom case (different patient) Case 13 Fever, proptosis Diagnosis? 1. Orbital cellulitis 2. Uncomplicated sinusitis 3. Mucocele 4. Subperiosteal abscess • A complication of acute sinusitis, particularly ethmoid • Note opacification of maxillary sinus and ethmoid air cells, as well as dehiscence of the lamina papyracea (often not present) • Abscess is seen as a rim-enhancing fluid collection abutting the medial orbital wall displacing intraorbital contents. Note medial rectus myositis • Treatment consists of IV antibiotics and often surgical drainage, especially with decreasing vision Case 14 Former smoker, decreased “eye movement” OD Diagnosis? 1. Pseudotumor 2. Thyroid associated orbitopathy 3. Metastasis 4. Schwannoma • Metastatic disease is favored in this case (note history!) • Asymmetric involvement and lack of spindleshaped EOM makes TAO less likely. Pseudotumor is typically accompanied by infiltration of orbital fat. A schwannoma should not be centered in an EOM. • Note marked enlargement, enhancement, and hyperintense T2 signal of the inferior rectus muscle Case 15 Painless proptosis Diagnosis?: 1. Optic neuritis 2. Schwannoma 3. Optic glioma 4. Perioptic meningioma Ans. 2 Schwannoma (V1) • Relatively rare (1% of orbital tumors) • Benign and slow-growing painless proptosis • May be isolated or associated with NFII. Arise from cranial nerves (excluding the optic nerve) • Fusiform to oval shape, iso to hypointense T1 signal and hyperintense T2 signal; they avidly enhance uniformly • Often displace the optic nerve (here inferomedially). • Note extension through the superior orbital fissure into the cavernous sinus Case 16 Painless facial swelling; Diplopia on left lateral gaze Diagnosis? 1. Paget disease 2. Ossifying fibroma 3. Intraosseous meningioma 4. Fibrous dysplasia Ans. 4 Fibrous dysplasia (FD) • Results when normal trabecular bone is replaced by fibrous tissue and immature, woven bone. • CT imaging findings include expanded bone with intact cortex and ground glass CT attenuation • Classic MR features include hypointense T1 and T2SI and variable contrast enhancement. • FD can be observed until there is functional impairment. Treatment consists of surgical excision, not usually attempted until after puberty • Rarely, FD can undergo sarcomatous degeneration Case 17 History withheld Diagnosis? 1. Paget disease 2. Ossifying fibroma 3. Osteoma 4. Meningioma Ans. 3 Orbital Roof Osteoma Mature, benign, slow-growing, osseous tumors. Often asymptomatic and discovered incidentally. Excision generally only required if mass effect May be “ivory” and appear as dense, compacted cortical bone, or “mature” with central marrow • This is an ivory osteoma: CT-marked uniform hyperdensity; hypointensity on T1 and T2WIs. Gardner syndrome must be excluded if a • Lesion displaces optic nerve inferolaterally • • • • patient is found to have multiple osteomas! Case 18 Periorbital pain and swelling Most likely diagnosis?: 1. Langerhans cell histiocytosis (LCH) 2. Paget disease 3. Intraosseous meningioma 4. Fibrous dysplasia Ans. 1 Langerhans Cell Histiocytosis (eosinophilic granuloma) • Rare disorder characterized by the abnormal proliferation of Langerhans cells • Term eosinophilic granuloma is used for unifocal disease, as in this case. Two additional syndromes, Hand-Schuller-Christian and Letterer-Siwe disease, refer to multifocal involvement within a single organ system and widespread multi-organ system disease, respectively • Imaging includes “punched out” lytic lesions with associated homogeneous soft tissue mass, often creating a “beveled edge” appearance • Orbital LCH is a risk factor for developing diabetes insipidus Case 19 “Raccoon eyes”, child with history of abdominal mass Diagnosis? 1. Langerhans cell histiocytosis 2. Neuroblastoma mets 3. Intraosseous meningioma 4. Fibrous dysplasia Ans. 2 Neuroblastoma Metastases • Frequently metastasizes to the skull. Although rare, bilateral metastases may produce “raccoon eyes” on physical exam • Result in aggressive bony destruction. Extradural, intracalvarial extension can occur, as in this case. • Avid contrast enhancement. There may also be significant mass effect on intraorbital contents, also present in this case • Abdominal CT shows the primary tumor of heterogeneous density with calcification, typical of neuroblastoma Summary • Extra-ocular orbital lesions may present a diagnostic challenge to the radiologist, especially when atypical in appearance • Careful inspection for characteristic distinguishing features will often lead to the correct diagnosis or significantly narrow the differential • Consider both common and uncommon entities when faced with these cases References • • • • • • • Bahn RS. Graves' ophthalmopathy. N Engl J Med. 362(8):726-38, 2010. Shams PN et al. Optic neuritis: a review. Int MS J. 16(3):82-9, 2009. Smoker WR et al. Vascular lesions of the orbit: more than meets the eye. Radiographics. 28(1):185-204; quiz 325, 2008. AnsariSA, Mafee MF. Orbital cavernous hemangioma: role of imaging. Neuroimaging Clin N Am. 2005; 15: 137–158. Ruggieri M et al. Earliest clinical manifestations and natural history of neurofibromatosis type 2 (NF2) in childhood: a study of 24 patients. Neuropediatrics. 36(1):21-34, 2005. Erly WK et al. Orbital histiocytosis X. AJNR Am J Neuroradiol. 16(6):1258-61, 1995. Alexander AA et al. Paranasal sinus osteomas and Gardner's syndrome. Ann Otol Rhinol Laryngol. 116(9):658-62, 2007. Contact Information jason-b-mueller@uiowa.edu