Epithelioid angiomyolipoma of the kidney

Abstract

A 37-year-old female was referred to our department for a renal mass which was incidentally found during a medical check-up. She had no history of tuberous sclerosis. Computed tomography and magnetic resonance imaging showed a 1.5-cm enhancing mass at the lower pole of the left kidney. An open partial nephrectomy was performed for a pre-operative diagnosis of renal cell carcinoma. Pathological examination revealed sheets of large polygonal epithelioid cells that showed positive immunostaining for HMB-45, which confirmed the diagnosis of an epithelioid angiomyolipoma. The patient remained free of recurrent or metastatic disease at 3 months of follow-up. Epithelioid angiomyolipoma is a recently identified variant of angiomyolipoma, which is sometimes associated with aggressive clinical behavior including local recurrence and metastasis. We present this case and review the literature concerning this unusual disorder.