[Malignant transformation of an intracranial epidermoid cyst].

We report the case of a 56-year-old man who underwent removal of an intracranial epidermoid cyst 16 years ago. The cyst recurred 12 years later and was once again almost completely removed. A new recurrence 4 years later proved to be due to malignant change in the form of squamous cell carcinoma. Only 17 other cases of malignant change in an intracranial epidermoid cyst have been reported. Moreover, three other cases presented as primary intracranial squamous carcinoma.