Intradiploic epidermoid cysts of the skull: a report of four cases.

Epidermoid cysts are uncommon, benign and slow-growing lesions. They may often reach an enormous size without producing neurological symptoms. Intradiploic epidermoid cysts are nearly 25% of all epidermoids. They are derived from ectodermal remnants that stay within the cranial bones during embryonic development. Intradiploic epidermoid cysts can be located in any part of the skull. Two of our four cases were located in left occipital bone and the others were in the frontal bone. These tumours can occur at any age from the first to the seventh decade of life. Our cases had a mean age of 38.75 years (19-55 years). They may reach great sizes before the initial diagnosis and may produce major neurological signs. For good long-term prognosis, correct radiological assessment and complete removal of the tumour with its capsule are essential. We report four cases of intradiploic epidermoid cysts of the skull and analyse the clinical, radiological features and treatment of these lesions in the light of relevant literature.