Cavernous Hemangioma of the Cerebellopontine Angle With Remarkable Enlargement of the Internal Auditory Canal in a Child

Cavernous hemangioma (CH) is a benign vascular malformation. Those arising in the central nervous system commonly occur in the supratentorial region or brainstem, but those originating from cranial nerves are rare. The case was an 11-year-old girl. Presenting with left sensorineural hearing loss and unsteadiness, she was found to have a tumorous lesion in the left cerebellopontine angle, accompanied by marked enlargement of the internal auditory canal. The left vestibular schwannoma was suspected, and tumor resection was performed. However, the intraoperative findings differed from this expectation, and only partial resection was achieved. Pathological examination confirmed the diagnosis of CH. Subsequently, the residual lesion regrew to the point of compressing the brainstem, necessitating total resection after facial nerve transection. Retrospectively, the imaging findings were atypical for vestibular schwannoma. Had CH been considered in the differential diagnosis from the outset, preparation for a single-stage operation might have been possible.