Squamous cell carcinoma as a late complication of intracerebroventricular epidermoid cyst. Case report.

Primary intracerebral squamous cell carcinoma is a rare sequela of benign cerebral epidermoid cysts. A case of presumed malignant transformation in a lateral ventricular epidermoid cyst is described, in which squamous cell carcinoma arose 33 years after the surgical resection of a benign epidermoid cyst. Three years after diagnosis of malignancy, the patient remains functional with a slowly invasive tumor. This case provides a rare description of the natural history of forebrain squamous cell carcinoma, which would appear to be a more indolent tumor than previously realized.