The MRI findings suggested the diagnosis of lipoma of the IAC. Because of the pathophysiology of this disease process, no surgical intervention was pursued. A follow-up MRI scan and an audiogram obtained 1 year later revealed no change.
Lipomas of the intracranial cavity are rare, accounting for only 0.1% of all cerebral tumors. Approximately 50% of intracranial lipomas are located adjacent to the corpus callosum. More than 90% of IAC lesions are acoustic neuromas, followed by facial neuromas, cholesteatomas, and meningiomas. Lipomas represent fewer than 0.14% of tumors that occur in the cerebellopontine angle (CPA). According to a 1998 review article by Bigelow et al,1 a total of 84 cases of lipomas located in the IAC and/or the CPA have been reported in the world literature; of these, 27 were limited to the IAC.1-4