Malignant PEComa of the skull base.

Perivascular epithelioid cell tumors (PEComas) are rare, usually benign lesions comprising a family of neoplasms including angiomyolipoma, lymphangioleiomyomatosis, clear cell "sugar" tumors, and clear cell myomelanocytic tumors. This report describes an apparent case of a malignant PEComa of the skull base in a 49-year-old woman, a previously undescribed location for this lesion.