True about acoustic neuroma:

(b) Arises from vestibular nerve(Ref. Shambaugh, 6th ed., 645)The most common site of origin of acoustic neuroma is from the Schwann cells of the inferior vestibular nerve followed by superior vestibular nerve.Acoustic neuroma is the most common benign tumour of the CP angle.When the tumour invades CP angle its upper pole compresses trigeminal nerve which is situated at the upper pole of CP angle.9th, 10th and 11th cranial nerves present at the base of CP angle are compressed by the lower pole of Acoustic neuroma.