Fig. 1

Preoperative MRI imaging and auditory test results. A Preoperative MRI showed a 23 mm well-defined, non-uniformly enhanced left internal ear canal tumor. B The tumor is distributed along the internal ear canal from the fundus to the cistern. C, D Preoperative audiological tests show bilateral profound hearing loss in the pure-tone audiometry (C), and only a slight wave V could be detected in the ABR in the left ear