Unusual lesions of the internal auditory canal.

Tumor types other than acoustic neuromas are uncommonly encountered in the cerebellopontine angle, and unusual lesions limited to the internal auditory canal (IAC) are given more rare. We present five patients with unusual tumors of the IAC including two meningiomas, two arachnoid cysts, and a hemangioma. These unusual tumors, and lipomas, are discussed. Particular attention is paid to the pathophysiology of the lesions and treatment recommendations. The differential diagnosis of intracanalicular lesions using magnetic resonance imaging is also presented.