Primary meningioma of the internal auditory meatus.

Background: Meningiomas originating in the internal auditory meatus are rare and have been reported in only 12 cases. Patient: We report about another case, which showed primarily the symptoms of sudden hearing loss and diagnostic signs of an intrameatal acoustic neuroma. The ABR interpeak latency IV was prolonged. The tumor was detected by MRI scan with gadolinium contrast enhancement and resembled the features of an intrameatal acoustic neuroma. Results: The tumor was removed via a middle fossa approach with preservation of hearing and facial nerve function. Histological examination however revealed a meningioma originating from the internal auditory meatus. Conclusions: Contrast enhancing intrameatal tumors are most often acoustic neuromas. However even despite subtile audiological and neurotological examination and sophisticated imaging techniques they cannot be differentiated clinically from meningiomas at this location. Removal of the intrameatal tumor via a middle fossa approach seems to be the best surgical approach to preserve hearing and facial nerve function.