a progressively enlarging, benign rumor within the auditory canal arising from the eighth cranial (acoustic) nerve; the symptoms, which vary with the size and location of the tumor, may include hearing loss, headache, disturbances of balance and gait, facial numbness or pain and tinnitus. It may be unilateral or bilateral, called also acoustic neurilemoma or neurinoma, schwannoma,(Source: Dorland's Illustrated Medical Dictionary, 27th Edition) and cerebellopontine angle tumor (Source: Stedman's Medical Dictionary, 24th Edition).
Neurilemoma is a synonym for acoustic neuroma.