Epidermoid cyst - middle cranial fossa

Case contributed by Dr Farhad Farzam


Chronic headache and left side body weakness.

Patient Data

Age: 25 years
Gender: Female

A well-circumscribed lesion in the right middle cranial fossa (right temporal lobe and right basal ganglia) following CSF signal on most of MR sequences (mainly low signal in T1 WI, high signal in T2 WI without post contrast enhancement) with areas of incomplete FLAIR suppression (dirty signal). 

Hyper intense signal in DWI and similar ADC values to brain parenchyma

No drop out signal on GRE to suggest hemorrhage or calcification

The lesion exerts mass effect over the right lateral ventricle, right thalamus and midbrain with resultant midline shift to the left side. 

The lesion is also encasing the right middle cerebral artery. 

Multiple T2/FLAIR focal hyper intensities in the bilateral subcortical white matter may represent chronic ischemic changes. 

Case Discussion

Intracranial epidermoid cysts are slow-growing, benign, extra-axial lesions. They are common in cerebellopontine angles, however; rarely occur in the anterior, middle and posterior cranial fossa.

Intracranial epidermoid cysts mimic CSF signal in CT and most of MR sequences with exception of the DWI which shows diffusion restriction.

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Case information

rID: 69937
Published: 27th Jul 2019
Last edited: 27th Nov 2020
Inclusion in quiz mode: Included
Institution: Kabul University of Medical Science

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