Presentation
Recurrent seizure.
Patient Data
There is a large extra-axial lobulated lesion present in the right anterior temporal region and extending into the posterior aspect of the anterior cranial fossa. Associated mass effect on the adjacent right inferior frontal lobe and right temporal lobe. Right amygdala is displaced superiorly. It is of low signal intensity on T1, high signal intensity on T2 with incomplete FLAIR suppression and diffusion restriction. There is minor peripheral contrast enhancement.
Conclusion: Appearance of this extra-axial lesion is suggestive of an epidermoid cyst.
Case Discussion
The patient underwent craniotomy for resection of the lesion.
Histology
The sections show predominantly aggregation of laminated keratin. Short segments of a membrane composed of a lining of squamous epithelium arranged on a thin layer of collagen are noted. The squamous epithelium has a well developed granular layer. The overall features are of an epidermal cyst. No appendageal structures are identified. There is no evidence of tumor.
FINAL DIAGNOSIS: Epidermoid cyst.