Dedifferentiated liposarcoma occurs in less than 10% of all liposarcoma and is found most often in the retroperitoneum and extremities. Histologically, the tumor was composed of well-defferentiated liposarcomastous areas with malignant fibrous histiocytoma-like area, peculiar neurallike whirling pattern associated and focal metaplastic bone formation. The rare radiologic feature of this have not been sufficiently described in the previous literature, and we now report a case of dedifferentiated liposarcoma in the thigh.