My brother has developed acoustic neuroma. what is it exactly?

Tumor of ear nerve: It is a benign growth of the nerve that goes from the brain to the inner ear. It can cause hearing loss and dizziness. When small sometimes they can just be followed to make sure that they don't grow and cause problems. Other times they can be treated with radiation treatments and sometimes they need to be removed surgically. They are not malignant. They do not spread.