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). (Neuroma is derived from Greek, meaning "nerve tumor".) The term "acoustic" is a misnomer, as the tumor rarely arises from the acoustic (or cochlear) division of the vestibulocochlear nerve.