Primary intracranial epidermoid carcinoma.

The cytologic findings in the cerebrospinal fluid in a case of primary intracranial epidermoid carcinoma are presented. The presence of a few squamous cells showing hyaline cytoplasm compatible with keratinization suggested the possible nature of the tomographically observed lesion. These tumors may arise in congenital epidermoid cysts at the base of the brain. Because of their location and meningeal spread, such tumors may cause severe symptoms and death despite a minute size, as illustrated by this case.