A 33 year-old woman complained of slowly progressive left facial palsy and a tumor in the external auditory meatus. The tumor had destroyed the mastoid process and the inferior wall of the external auditory meatus, and extended to the posterior fossa dura and to the deep skull base anterior to the styloid process. A review of the Japanese literature since 1937 revealed 20 cases of facial nerve neurinoma originating from the vertical portion of the Fallopain canal. The common clinical presentation and symptoms in most cases were progressive facial palsy and tumor in the external auditory canal. We would like to emphasize that facial nerve neurinoma in the temporal bone is not as rare as has been commonly believed and that patients with facial nerve palsy, especially if it increases gradually over weeks and months, should be examined completely in order to find it in the early stages.
