Epithelioid Angiomyolipoma: A Case Report

Epithelioid angiomyolipoma is a recently recognized tumor entity. We report a case of epithelioid angiomyolipoma of the kidney that occurred in a 70-year-old female. The patient presented with massive abdominal hemorrhage and shock. There was no history of tuberous sclerosis complex. The tumor consisted of smooth muscle, adipocytes, small-to-medium-sized hyalinized blood vessels and numerous pleomorphic epithelioid cells with clear to eosinophilic cytoplasm. Mitosis was exceptional and no glandular pattern was recognizable. Immunohistochemically the epithelioid cells were strongly positive for HMB45 and CD68, focally positive for S-100, actin and vimentin, and negative for epithelial markers including epithelial membrane antigen and cytokeratins. Previous reports in the English literature suggest that epithelioid angiomyolipoma may have malignant potential. In our case, at six months from surgery the patient is alive and well without evidence of relapse or metastasis.