Vascular lesions of the internal auditory canal.

We report here two cases of vascular tumors arising within the internal auditory canal, both of which presented with cerebellopontine angle symptoms and simulated acoustic neurinomas. The first case was an arteriovenous malformation that caused moderate sensorineural hearing loss, tinnitus, vertigo with lateropulsion, facial weakness, and trigeminal hypoesthesia on the same side. The second case was a venous angioma, to our knowledge the first ever reported in this location, which presented with sudden complete deafness and progressive hemifacial spasm. The latter subsided completely after successful total extirpation of this unique tumor. The literature on these extremely rare lesions is also reviewed.