Acoustic neuroma

[Luis Fok]

An acoustic neuroma (more correctly known as a vestibular schwannoma) is a noncancerous (benign) tumor that originates in the cells that wrap around the vestibular nerve (Schwann cells).
These tumors arise from the vestibular (balance) nerve, which is one branch of the vestibulocochlear nerve (8th cranial nerve). The other branch, the cochlear (auditory) nerve, carries sound signals to the brain. Early symptoms as the tumor grows and presses on the auditory nerve include slowly progressing hearing loss in one ear (hence the historical name acoustic neuroma).
(See also Overview of the Inner Ear.)