[Massive hemorrhage within an acoustic neurinoma. Case report].

A 39-year-old male experienced unilateral right hearing loss and tinnitus for 7 years and was hospitalized after he suddenly developed severe headache, vertigo, and right facial paralysis. Computed tomography (CT) showed a round, high-density are in the right cerebellopontine angle. Magnetic resonance (MR) imaging demonstrated a crescent-shaped region of high signal intensity, representing hemorrhage, in the superior aspect of the tumor, surrounded by edema. The right internal auditory canal was enlarged. Four-vessel angiography disclosed neither an aneurysm nor an arteriovenous malformation. A right suboccipital craniectomy revealed an encapsulated mass 3 cm in diameter in the right cerebellopontine angle. The tumor was totally removed. Histological examination revealed a typical neurinoma composed of Antoni type A and B cells. After undergoing anastomosis of the right hypoglossal and facial nerves, the patient was discharged in good condition. In this case MR imaging demonstrated intratumoral hemorrhage (which is rare in cases of acoustic neurinoma) and the surrounding tissue more clearly than did CT scanning.