DEDIFFERENTIATED LIPOSARCOMA OF THE SUBCUTIS

This report describes an 82-year-old woman with dedifferentiated lipos arcoma, an extremely rare neoplasm of the subcutis. The patient had fi rst recognized a very soft mass in the anterolateral part of the right thigh more than 20 years earlier, but because the tumor showed little change over this period, she did not seek treatment. She recently not iced a hard, rapidly growing mass within the former tumor. Both magnet ic resonance imaging and axial computed tomography revealed a subcutan eous fatty lesion measuring 12 x 7 x 4 cm and a well-delineated mass-l ike area (4 x 3 x 3 cm) of nonfatty tissue within the lesion. Histolog ically, the former was a mature lipomatous tumor with broad fibrous se pta containing some atypical stromal cells, and the latter was a much more cellular, spindle cell tumor with a malignant fibrous histiocytom a-like pattern. The authors propose that dedifferentiated liposarcoma is not restricted to the deep soft tissues and may develop in the subc utis and further suggest appropriate surgical management for well-diff erentiated fatty tumors of subcutaneous origin.