Epithelioid variant of pleomorphic liposarcoma: report of a case.

A case of an epithelioid variant of pleomorphic liposarcoma (PL) arising in the back of a 72-year old male is presented. The lesion was a well-circumscribed but unencapsulated, yellowish white mass measuring 11 x 10 x 9 cm in the subcutis and muscle. Histologically, the tumor consisted of three elements; an epithelioid cell element occupying about 50%, a lipogenic and mixed lipogenic and epithelioid cell element occupying 40%, and a malignant fibrous histiocytoma-like element. The lipogenic area was composed of uni- and multivacuolated pleomorphic lipoblasts. Immunohistochemically, the tumor was positive for vimentin, epithelial membrane antigen, and CD10. It was negative for desmin, alpha-smooth muscle actin, muscle actin, S-100 protein, and cytokeratins 8 and 18. The epithelioid variant of PL should be differentiated from metastatic renal cell carcinoma and adrenal cortical adenocarcinoma.