Malignant epithelioid angiomyolipoma in the kidney and liver of a patient with pulmonary lymphangioleiomyomatosis: lack of response to sirolimus.

A 26-year-old woman with lymphangioleiomyomatosis (LAM) was hospitalized for the surgical excision of a giant abdominal tumor of right kidney origin. The pathological diagnosis of the tumor was conventional angiomyolipoma (AML). After 8 months, 2 liver tumors appeared and grew rapidly. The tumors were resected, and the pathological finding of these tumors was epithelioid AML. Thereafter, metastatic multiple lung tumors appeared, and there was local recurrence of the liver tumors. Sirolimus, an mTOR protein inhibitor, was used to treat epithelioid AML. However, the drug did not inhibit the rapid growth of the tumor at all. This finding suggests that sirolimus might not be effective against epithelioid AML, and in such cases, complete surgical resection should be the treatment of choice.