Primary intracranial squamous cell carcinomas: report of two cases.

Two cases of primary intracranial squamous cell carcinomas are reported. The first patient is a 57-year-old man with an epidermoid carcinoma in the right cerebellopontine angle, having histological features that indicated malignant transformation in a benign epidermoid cyst. The second patient is a 42-year-old man in whom squamous cell carcinoma arose in a pre-existing middle fossa dermoid cyst 9 years after the initial surgical resection. The literature on primary intracranial squamous cell carcinomas is reviewed, and the clinical features and histological pathogenesis for the occurrence of this unique condition are discussed.