Temporal bone pathology in intracochlear schwannoma with profound hearing loss.

Intracochlear schwannoma was found in the temporal bone of a 85-year-old man in whom audiometric study, 26 days before death, had shown total deafness in the left ear. The tumor occupied the entire lumen of the cochlea in the basal turn involved Rosenthal's canal, but it occupied only the scala tympani in the second turn. Intralabyrinthine schwannomas are difficult to diagnose by clinical examination. They were discovered accidentally during destructive labyrinthectomy for presumed Ménière's disease or discovered incidentally by postmortem temporal bone pathology. Although intralabyrinthine schwannomas are a rare occurrence and cannot usually be diagnosed without surgery or postmortem histopathology, it is important to suspect the possibility of their existence in differential diagnosis of atypical Ménière's disease or unilateral idiopathic progressive deafness. Long-term follow-up is obviously necessary to exclude the tumor.