Intradiploic frontal epidermoid cyst in a patient with repeated head injuries: is there a causative relationship?

Epidermoid cysts are rare disontogenetic tumoral lesions in the cranial compartment (1% of all intracranial tumors) and are usually located in relation to the cranial sutures; the intradiploic location is the less frequent. We report a clinical case in which the post-traumatic etiology of a frontal intradiploic epidermoid is considered. The histological findings revealed the presence of an epidermoid tumor associated with a typical foreign body inflammatory reaction, after repeated head traumas at the site of the tumour. This is the first case in whom the association between this tumoral lesion and a tissue inflammatory reaction due to foreign bodies is demonstrated.