Vestibular schwannoma (acoustic neuroma)

Overview

A benign tumour of the vestibulocochlear nerve’s Schwann cells at the cerebellopontine angle. The classic presentation is UNILATERAL sensorineural hearing loss with tinnitus; as it grows it affects adjacent cranial nerves (V, VII). Bilateral tumours suggest neurofibromatosis type 2.

Recognise

• Unilateral sensorineural hearing loss + tinnitus (the key early features) ± vertigo/imbalance
• Larger: facial numbness (CN V, absent corneal reflex), facial weakness (CN VII), cerebellar signs
• Bilateral vestibular schwannomas = neurofibromatosis type 2

Differentials & how to tell them apart

Investigations

MRI of the internal auditory meatus/cerebellopontine angle (the diagnostic test); pure-tone audiometry (asymmetric sensorineural loss).

Management

MRI to diagnose; manage by size — observe, microsurgery, or stereotactic radiosurgery

1. 1Asymmetric sensorineural hearing loss → MRI of the cerebellopontine angle. Manage by size/growth/symptoms: serial observation, stereotactic radiosurgery, or microsurgical excision.Gate: Any UNILATERAL/asymmetric sensorineural hearing loss should be imaged (MRI) to exclude a vestibular schwannoma — do not attribute it to age
2. 2Bilateral tumours → investigate for neurofibromatosis type 2 (genetics); monitor facial-nerve function with treatment.

Monitor & prognosis

Hearing, facial-nerve function, tumour growth on serial MRI.

Benign and slow-growing; good outcomes with timely treatment.