Extradural dermoid cyst of mastoid bone: a case report

Dermoid cysts of the head and neck are rare congenital benign tumors. According to the literature they represent about seven percent of all dermoids and less than one percent of all intracranial neoplasms. Extradural dermoid cysts are very rare. We report a case of intracranial extradural dermoid cyst of mastoid bone. We believe that this is the second documented extradural dermoid cyst, the first case reported in the literature (Ammirati et al., 2007) was in close relation to the petrous apex but ours is in close relation to mastoid antrum. Hearing loss was the only clinical presentation in this case, while neurological symptoms were the main presenting symptoms in the first reported case. We present our management of this rare case with respect to the clinical, radiological, histopathological, and surgical aspects and conclude that dermoid tumors, though rare, need to be included in differential diagnosis of middle ear lesions.