Hypervascular intracisternal acoustic neuroma.

The diagnosis of acoustic neuroma is usually evoked in a patient presenting with a long history of hearing disturbance in whom an enhancing lesion within the internal auditory canal and/or the cerebellopontine angle is found on MRI. Hypervascularity with arteriovenous shunting and early filling of enlarged veins is a common feature of malignancy and has been reported very rarely in benign acoustic neuroma. We present the case of a patient without hearing disturbance, who showed a highly vascular lesion with no component in the internal auditory canal, making the preoperative diagnosis of acoustic neuroma very challenging. We discuss here the intracisternal site of origin and hypervascularity of acoustic neuroma, and also the differential diagnoses and management of such tumors.