False-positive MRI and CT findings of an acoustic neuroma.

CT and MRI are excellent imaging modalities available in the work-up of a patient with suspected acoustic neuroma. A case is presented where both CT and MRI suggested the presence of a small acoustic neuroma. Exploration of the cerebellopontine angle and internal auditory canal revealed no evidence of a tumor. A vascular loop around the inferior and superior vestibular nerves was identified and decompression completely eliminated the symptoms. Even with today's sophisticated diagnosis tools available to evaluate a suspected acoustic neuroma, the definitive diagnosis and subsequent treatment may change at surgery.