DEDIFFERENTIATED LIPOSARCOMA WITH AN INFLAMMATORY MALIGNANT FIBROUS HISTIOCYTOMA-LIKE COMPONENT PRESENTING A LEUKEMOID REACTION

A rare case of dedifferentiated liposarcoma (well-differentiated lipos arcoma with an inflammatory malignant fibrous histiocytoma (MFH)-like anaplastic component) occurring in a 69-year-old male is presented. Th e patient had noticed a dull pain in his left loin and thigh for about 1 month, Computed tomography examination revealed a low-density mass lesion, measuring about 6 cm in diameter, in the left iliopsoas muscle , and if was surgically removed. Grossly, the lesion was composed of a n encapsulated, soft, whitish mass and an adjacent, well-demarcated, y ellowish hard nodule, measuring about 2.5 cm in diameter, Microscopica lly, both lesions showed features of an inflammatory variant of MFH an d a sclerosing type of well-differentiated liposarcoma, respectively. to our knowledge, only two cases of dedifferentiated liposarcoma combi ned with inflammatory MFH as a dedifferentiated component have been re corded in the literature. The salient feature of the present case is a systemic inflammatory reaction, as shown by prominent leukocytosis (u p to 73 900/mm(3)) and the elevated serum value of C reactive protein (up to 26.0 mg/dL), which were transiently reduced after surgery, The inflammatory reaction was suggested to be induced by cytokines, such a s granulocyte colony-stimulating factor and interleukin-6, which were probably produced by the tumor cells in the present case, because the elevated serum values of those cytokines were decreased after surgery.