Epidermoid
Findings:
Multiple MR images demonstrate a lobulated nonenhancing mass within the suprasellar and prepontine cistern. The lesion causes mass effect on the pons. The FIESTA images demonstrate slight decreased T2 signal compared to CSF. The infiltrative extraaxial mass is associated with restricted diffusion.
Discussion:
nCongenital epidermal inclusion cyst
n90% intradural, 40-50% CPA, rare intraaxial
nMultilobulated, infiltrative, encasing CN/vascular, mass effect, CT/MR near CSF
nUncommon: Ca++ 10-25%, “dense” epidermoid due to hemorrhage/protein/saponification
nNonenhancing or minimal rim enhancing, nodular enhancement indicates malignant degeneration
DWI+ is most helpful imaging feature
nPathology
nCongenital- epidermal inclusion
nAcquired- rare intracranial, more common in spine after LP
n“Mother of Pearl” gross appearance, cauliflower like, multilobulated
nLined by stratified squamous cuboidal epithelium, fibrous capsule, contain cholesterol and keratin debris w no dermal appendages
nClinical
nVery slow growing, often clinically silent until large- headaches, CN neuropathy, uncommon sz, peak 40 yo w no sex predom, chemical meningitis if rupture, rare malignant degeneration
nRx
nMicrosurgical resection, common recurrence, subarachnoid dissemination, chemical meningitis.
nRare malignant degeneration after multiple recurrences
BACK
TO MAIN PAGE