A petrous bone destructive acoustic neurinoma: a tumor of far-lateral origin?

We report a case of an acoustic neurinoma that recurred more than 11 years after "total" tumor removal through the posterior cranial fossa. Recurrent tumor had obliterated the petrous bone, filled the middle ear, and was visible grossly at the external auditory meatus. The unique behavior of this tumor implied that the site of origin was within the labyrinth, beyond the fundus of the internal auditory canal and far lateral to the usual site of acoustic neurinoma origin. We offer an hypothesis as to why these tumors occasionally recur, even after clinical "total" removal.