Focal rhabdomyosarcomatous differentiation in primary liposarcoma.

A unique case of primary myxoid liposarcoma of the thigh, in which focal pleomorphic areas were present containing rhabdomyoblasts, is described. Focal rhabdomyosarcoma in liposarcoma has only rarely been reported previously and only in dedifferentiated liposarcomas of the retroperitoneum. All but one have been recurrences with rhabdomyoblasts being absent in the primary liposarcoma. As rhabdomyoblasts were only focally present, the present case is regarded as liposarcoma with focal divergent rhabdomyoblastic differentiation rather than malignant mesenchymoma.