[Current topics in the diagnosis and treatment of malignant fibrous histiocytoma].

Malignant fibrous histiocytoma (MFH) is a tumor about which much remains unknown. The cell origin, molecular mechanism of pleomophism and mechanism of pleomorphic change in a cell undergoing malignant change have not been elucidated. MFH-like histological changes are observed in many bone and cartilage sarcomas, and some renal cell carcinomas and malignant lymphomas. These changes occur in many subtypes of sarcomas such as osteogenic sarcoma, chondrosarcoma, leiomyosarcoma, rhabdomyosarcoma, and liposarcoma. MFH has been regarded as one tumor classification from its special histopathological features. In clinical pathological studies these tumors are divided into low-grade fibrous tumors and fibrous histiocytic tumors. With the establishment of molecular biological diagnostic methods, MFH-like histological features can be seen in changes in cellular differentiation of many sarcomas. Patients with MFH often have repeated recurrences before a diagnosis is made, and the tumor is partially resected. Furthermore, distance metastasis develops and the prognosis is poor. The sensitivity of MFH to radiotherapy and chemotherapy is insufficient, and evidence is lacking for adjuvant treatment. Rescue following initial treatment failure is extremely difficult. Local control of 70% to 90% can be achieved if a correct diagnosis is made, and a curative wide resection or salvage wide resection are done early. For treatment of bone and soft tissue sarcoma, a correct diagnosis and initial treatment are extremely important. MFHs are rare tumors that occur in every part of the body. Many cases need to be accumulated in joint clinical studies across fields according to organ and specialty, and effective treatment method developed. We need to advance the standardization of treatment for MFH, and eliminate wrong initial treatment through the active provision of information.