Asymptomatic intracochlear neurinoma. A temporal bone report.

A small intracochlear neurinoma was found in the temporal bone of a 54-year-old man who had no history of hearing loss or dizziness. The tumor was small, confined to the scala tympani, and did not visibly alter the tissues around it. The neurinoma was derived from the distal processes of the cochlear neuron. Intralabyrinthine tumors can cause auditory and vestibular symptoms and are difficult to diagnose.