July 14 Cases 1-3 answers

Case 1 - 2 different examples of Meningioma.

Case 2 - BB to the eye.

Case 3 - Epidural hematoma.

Sorry my family got back from long trip so not a lot of time for detailed descriptions. Will do more later promise.

As far as Case 2 - the movie was -

Case 1 Answer 7-6-2009 Thyroid (Grave's) Ophthalmopathy

What we see is enlargement of the extraocular muscles that "spares" the myotendinous junction.

This is Thyroid Ophthalmopathy

• Usually occurs in patients with Grave's disease - but can be seen in any thyroid state


• Resolves in >90% of patients


• Most common cause of proptosis in adults


• Histology - inflammatory leukocytic infiltration with edema and deposition of mucopolysaccharides - leading to fibrosis, lipomatosis, fatty degeneration.


• Can compress optic nerve leading to optic neuropathy


• Can cause diplopia due to muscle entrapment


• Proptosis - can lead to corneal ulcers and conjunctival congestion


• Most frequently involves medial and inferior recti - IMSLow - Inferior, medial, superior, lateral; muscles >4 mm


• More frequent in women but more severe in men


• Expansion of orbital fat


• Upper and lower eyelid retraction


• Often bilateral and symmetric


• Painless


• TX - prednisone, radiotherapy, surgical decompression, thyroid surgery, I-131


• DDX - pseudotumor (painful, unilateral, involves tendons, inflammed fat, good response to steroids) [can be idiopathic, sarcoid, endocrine, focal infections, foreign bodies], cavernous hemangioma of the orbit, Histiocytosis X, cavernous sinus thrombosis, intraconal varices, lacrimal gland tumor and don't forget mets (usually osseous)


• Imaging - Ultrasound, CT (good bone imaging and shows all the features but has radiation), MRI

References: http://emedicine.medscape.com/article/383412-overview ; Neuroradiology Companion by Mauricio Castillo and Primer of Diagnostic Imaging by Weissleder et al.

Case 2 Answer 7-6-2009 - Perineural spread.

The imaging demonstrates a lesion in Meckel's cave that is low on T1, dark on T2 and enhances. There is denervation atrophy of the pterygoid muscles on the right and opacification of the right mastoid air cells.

With imaging like this, you need to think of peritumoral spread along the cranial nerves. This is an odd example in that biopsy revealed Lymphoma.

• Perineural spread - tumor or other pathology spreads along tissues of neural sheath
• Common in head and neck cancer
• In head and neck cancer - major negative prognostic indicator
• Most common malignancies - salivary, mucosal and cutaneous
• Adenoid cystic frequently spreads by perineural tumor spread
• SCC of mucosal and cutaneous can
• Desmoplastic melanoma is common
• Often present at time of diagnosis; rarely present prior to detection
• Can present as recurrence or occur at the same time as recurrence
• Common hx - new cranial neuropathy
• Any tumor that are adjacent the skull base foramina are at risk of Perineural tumor spread; esp - masticator space, Meckel's cave, cavernous sinus and Pterygopalatine fossa
• Perineural spread - can be retrograde (toward CNS) or antegrade (away from CNS)
• Benign - some benign disorders spread along cranial nerves (essentially like PNS or similar to it by imaging) - schwannoma/neurofibroma, meningioma, rhinocerebral mucormycosis, sarcoidosis etc.
• Signs and Symptoms - pain and paresthesias
• V3 - weakness and denervation of muscles of mastication
• Facial - variable weakness or paralysis
• Most commonly affected - trigeminal and facial
• V2 (maxillary) and V3 (mandibular) - most common branches of CN V involved
• V1 - sensory to eye, lacrimal gland, conjunctiva, some nasal mucosa and upper face
• V1 - often from cutaneous lesion in supraorbital region; rare for intraorbital process to spread to V1
• V2 - sensory to mid and upper lateral face, mucosa of palate, sinonasal region, maxillary gingiva and maxillary teeth
• V2 - to spread along V2 from nasopharynx - must access pterygopalatine fossa (PPF) - often by nasal cavity then sphenopalatine foramen
• V2 - from skin along maxillary distribution - infraorbital nerve or zygomatic nerve
• Pterygopalatine fossa - Pterygopalatine ganglion, internal maxillary artery; bounded posteriorly by pterygoid plates, medially by palatine bone, anteriorly by maxillary sinus
• PPF - communicates laterally with infratemporal fossa with pterygomaxillary fissure
• PPF - communicates w/ intracranial space by foramen rotundum
• PPF - communicates with nasal cavity (medially) via sphenopalatine foramen
• PPF - Vidian nerve provides preganglinonic parasympathetic component of pterygopalatine ganglion
• PPF - communicates with greater and lesser palatine foramina inferiorly through the palate
• V3 - sensory innervation to skin of lower face and pre-auricular/temporal region, mandibular teeth, mucosa of mandibular gingiva, floor of mouth, ant 2/3 of tongue, buccal mucosa
• V3 - motor to musscles of mastication, mylohyoid and anterior digastric
• V3 - PNS - travel through foramen Ovale to Meckel's cave
• Facial Nerve (CN VII) - typically only 2 branches are affected - descending facial nerve (from parotid malignancies or lesions that involve the parotid) and the GSPN (greater superficial petrosal nerve)
• Descending facial nerve - can travel to geniculate ganglionand even through labyrinthine segment to involve internal auditory canal
• GSPN - small branch that leaves geniculate ganglion and exits superior surface of temporal bonte through facial hiatus to become intracranial; courses anteromedially beneath Meckel's cave to foramen Lacerum to join deep petrosal nerve (carotid sympathetic plexus) and become the Vidian nerve through Vidian canal
• Imaging - minimum need axial T1, axial T2, and 3 plane postcon T1 (with at least one in fat-suppressed form)
• T1 - look for loss of normal fat
• Look for widening of foramina - foramen ovale, mandibular foramen, foramen rotundum, PPF, foramen and canal for infraorbital nerve, vidian canal, palatine foramen, stylomastoid foramen, descending facial canal
• Look for enhancement
• Look for involvement of Meckel's cave
• Indirect findings - denervation of masticator muscles, anterior digastric, mylohyoid
• Early denervation - T2 bright and enhancement with post con
• Late - atrophy and fatty infiltration

Reference - MR Imaging of Perineural Tumor Spread by Lawrence E. Ginsberg; Neuroimaging Clinics of North America 14 (2004) 663-667

6-27-2009 Case 2 answer - Capillary Telangiectasia

Lesion that is not seen on T1 precon but demonstrates "stipple" enhancement on postcontrast images in the pons - this is consistent with capillary telangiectasia.

• Most are in pons - but can be seen in cerebral, cerebellar and spinal cord tissue
• Nearly always asymptomatic and no further intervention necessary
• 16-20% of intracerebral vascular malformations at autopsy
• CT - almost always normal
• T1 - hypo to iso to brain
• T2 - normal (often) or slightly hyperintense
• T2* - can be normal or low in signal - but not due to hemorrhage or calcification - and likely represents deoxyhemoglobin in slow flowing blood
• T1 postcon - brush like or stippled pattern
• No mass effect
• 2/3 have enlarged vessel that may represent a draining vein.
• Often considered an acquired lesion and may represent obstructed venous drainage
• Can be seen in association with cavernomas and AVMs
• Does not show up on angiography

Reference - http://www.ajnr.org/cgi/content/full/22/8/1553 and http://emedicine.medscape.com/article/337451-overview

6-27-2009 Case 1 Answer - Choroid Plexus Carcinoma

CT - demonstrates a hyperdense structure in the lateral ventricle causing hydrocephalus in a young patient. Pathology revealed a choroid plexus carcinoma.

• Neoplasms of ventricular system are usually easy to recognize but pathology is sometimes difficult to determine by imaging characteristics
• Choroid plexus - found in the ventricles - highly vascular and produces CSF
• Choroid plexus neoplasms - usually highly vascular and produce hydrocephalus
• Benign - papilloma; Malignant - carcinoma
• Most frequently found in atria and posterior portion of lateral ventricles
• Other highly vascular tumors are commonly seen in this site - mets and meningioma
• Ependymal cells - ependymoma
• Subependymal glial cells - subependymomas and subependymal giant cell astrocytoma
• Septum pellucidum - central neurocytoma
• Choroid plexus - found most commonly in atria, third ventricle and 4th ventricle (not seen in temporal horns or aqueduct of Sylvius)
• 50% of tumors are in lateral ventricles, 40% in 4th and 5% in 3rd.
• Rare - extraventricular areas like CPA, suprasellar cistern etc
• Choroid plexus tumors aren't that common overall but 10-20% of brain tumors in those less than 1 yr.
• 80% are benign papilloma and rest are carcinoma
• Those in lateral ventricle are most likely to present <10
• Most present due to symptoms of hydrocephalus
• Other symptoms - cranial nerve palsies, seizures, coma, and one report of psychosis
• Choroid plexus tumors - have an association with Li-Fraumeni and Aicardi syndromes
• Choroid plexus papilloma - 5 yr survival - practically 100%
• Choroid plexus carcinoma - 5 yr survival - 26-50%
• Choroid plexus tumors - cauliflower like well circumscribed masses with lobulations
• hemorrhage and cyst formation can be seen
• Signs of carcinoma - necrosis and parenchymal invasion
• Lateral ventricle choroid plexus - attached at trigone
• 3rd ventricle - attached at roof
• 4th ventricle - attached at posterior medullary velum
• Can have ball-valve effect for hydrocephalus
• Atypical choroid plexus papilloma - one or 2 histologic malignant features but not enough for carcinoma
• Papilloma and Carcinoma (but much more frequent for carcinoma) can have seeding of CSF
• CT - most tumors are iso or hyperattenuating
• CT - with enhancement - avid enhancement
• CT - 24% see calcifications
• T1 MR - iso or hypo to brain
• T2 - variable and often see flow voids within the lesion
• T1 postcon - avid enhancement
• Carcinoma - may have more variable CT and MR appearance; may have less hydrocephalus; look for parenchymal invasion and vasogenic edema
• Carcinoma - Increased uptake on FDG PET
• Imaging - papilloma and carcinoma has a lot of overlap therefore unless obvious malignant features are present cannot exclude carcinoma when imaging looks like a papilloma
• Lateral ventricular lesions - supplied by anterior choroidal, medial posterior choroidal and lateral posterior choroidal arteries
• 4th ventricular - choroidal branches of PICA
• Lesions in trigone - less than 10 - think papilloma/carcinoma; 10-40 - think low grade glial like ependymoma or subependymoma; >/= 40 - think meningioma, mets, lymphoma
• Intraventricular meningioma - rare and almost always older (caveat - 1/5 of all meningiomas in children are intraventrciular)

References - http://radiographics.rsnajnls.org/cgi/content/full/22/6/1473 and http://www.ajnr.org/cgi/content/full/20/5/882