Epidermoid tumors. Review of the literature.

Reports of epidermoid tumors from 1965 through 1986 were reviewed with emphasis on new and unusual findings. Clinical data considered were rapid onset, rare symptoms, size and rate of growth, and complications. Uncommon locations included multiple sites in one patient and the anterior fontanelle. The radiologic data from computed tomography were the main contributors to diagnosis. An immunohistochemical test disclosed that cells of craniopharyngiomas are keratin-positive. Histologically benign epidermoids can behave as highly malignant tumors, and can become carcinomatous. Postoperative results for benign tumors were often excellent. Evidence was presented of the close relation among epidermoid and dermoid tumor, craniopharyngioma, ameloblastoma (adamantinoma), Rathke's cleft cyst, and aural cholesteatoma.