Cerebellopontine angle lipoma.

Cerebellopontine angle lipomas are rare lesions that differ from other intracranial lipomas in that they typically present with slowly progressive focal signs and symptoms identical to those of other tumors of this location, and by their propensity for intimate involvement of the adjacent cranial nerves. The lipomas in this study demonstrated this tendency to splay apart and infiltrate the cranial nerves, with the fatty tissue adjacent to the nerves invariably containing portions of the cranial nerves. Hence, the dissection of the adipose tissue from the nerves led to greater than anticipated postoperative neurologic deficits. Therefore, minimal excision of tumor is recommended to achieve decompression. Since preoperative evaluation does not distinguish with certainty this lesion from others more common to this location, intraoperative examination of frozen sections is required to confirm the diagnosis.