A sarcoma characterized by the presence of fibroblasts and atypical, pleomorphic cells. Cellular pleomorphism and a storiform pattern are the microscopic characteristics that define this malignant tumor. Although it can occur in any part of the body, the lower extremity is the most common site of involvement. This is generally an aggressive sarcoma, although certain morphologic variants (e.g., myxoid malignant fibrous histiocytoma) tend to have a more favorable prognosis. - 2003