[Saccular aneurysm of the anterior-inferior (middle cerebellar)--internal auditory artery].

On the basis of data in the literature (4 cases) and one case observed by the authors themselves, a clinical characteristics is given of the rarely encountered aneurysm of the middle cerebellar-internal acoustic arteries. In the absence of subarachnoid hemorrhage the aneurysm produces a typical picture of neurinoma of the acoustic nerve. The patient described was operated on with the use of a surgical microscope. Clipping of the aneurysm resulted practically in full recovery of the patient.