Fusiform aneurysm of the basilar artery presenting as a cerebellopontine angle mass.

It is extremely rare that nonsaccular intracranial aneurysms are located at the cerebellopontine angle. A 60-year-old woman presented with dizziness and left-sided sensorineural hearing loss that had developed gradually for 6 months. Magnetic resonance imaging scan and magnetic resonance angiography revealed that the basilar artery was ectatic and markedly displaced to the cerebellopontine angle. The association between otoneurological findings and radiological findings is discussed.