An acoustic neuroma is a benign, noncancerous, often slow-growing tumor of the nerve which connects the ear to the brain (8th cranial or auditory) nerve.

Causes

These tumors are thought to arise when there is a defect in a certain tumor suppressor gene, which normally prevents tumors from occurring. The cause of the genetic defect is not known. However, acoustic neuroma is often linked with the genetic disorder neurofibromatosis type 2 (NF2).

Acoustic neuromas are relatively uncommon in general, but they are one of the most common types of brain tumors. They affect approximately 1 out of 100,000 people per year.

The tumor is most commonly located at the base of the brain, where the auditory nerve leaves the skull cavity and enters the bony structure of the inner ear.