Acoustic Neuroma
An acoustic neuroma, also called a vestibular schwannoma, is a benign primary intracranial tumor of the myelin-forming cells of the vestibulocochlear nerve (CN VIII). The term "acoustic neuroma" is a misnomer, as the tumor never arises from the acoustic (or cochlear) division of the vestibulocochlear nerve. Approximately 3,000 cases are diagnosed each year in the United States with a prevalence of about 1 in 100,000 worldwide. Incidence peaks in the fifth and sixth decades and both sexes are affected equally.