gms | German Medical Science

External ear canal cholesteatoma is a rare entity with an approximate reported incidence of 1 in 1000 new otologic patients. On the other hand autopsy studies suggest that single defects in the tegmen of the temporal bone occur in 15% to 34% of specimens. Both conditions may share common traumatic etiology, however their concurrence has not been reported.

We report a case of a 38 year old female referred for a left sided cholesteatoma of the external ear canal with destruction of the posterior canal wall. Careful examination of her CT found a dehiscence of the contralateral mastoid tegmen that had been overlooked by the referring institution. MRI revealed herniation of meninges and brain tissue into the mastoid antrum. Medical history elicited a car accident with multiple trauma and loss of consciousness and amnesia. However no CT was done at that time and cranial base fracture was not ruled out. Nevertheless, both conditions were attributed to the previous head trauma. The patient underwent conservative radical mastoidectomy of the left ear. Since right sided finding of meningoencephalocele was asymptomatic a follow-up was scheduled. Two years after surgery the patient is asymptomatic for both ears.