History
The classical presentation is gradual hearing loss and tinnitus that is usually present for years. Other cranial nerves may be affected but this is far less common. 0.02% of patients undergoing MRI will have an acoustic neuroma detected.
Very rarely, large tumours present due to compression of adjacent brainstem structures (eg. cerebellum) with resulting ataxia.
Patients with neurofibromatosis type II are typically found to have bilateral acoustic neuromas (95% by age 30)
Examination
Hearing loss is frequent on the affected side. Less commonly, patients have abnormalities detected in other cranial nerves. A full neurological examination should be done.
Imaging
MRI has largely replaced audiometry testing which used to be 'gold standard'. Tumours are characteristically located at the cerebellopontine angle and MRI can detect lesions as small as 1 mm. The lesions usually enhance well with contrast.
Histological Diagnosis
Histological diagnosis is only obtained when surgery is performed.
