Two cases of incidental epidermoid cysts: sphenoid sinus and temporal bone.

Epidermoid cysts or tumors are uncommon. When they do occur they are usually large at presentation, and the initial symptoms usually involve the cranial nerves. Congenital epidermoids are believed to arise as a result of cellular dysfunction during embryogenesis, which leads to an abnormal migration of ectodermal cells. We present 2 cases of epidermoids that were identified incidentally at our institution during radiologic evaluations of head trauma; one was found in the sphenoid sinus and the other in the temporal bone. Both patients were treated surgically. We review the pathogenesis, diagnosis, and imaging characteristics of these epidermoids.