[A case of retroperitoneal malignant fibrous histiocytoma with marked response to concurrent cisplatin and radiation therapy: a case report].

A 42-year-old male was referred to our hospital with a complaint of right lumbar pain in September 1999. Abdominal computed tomography and magnetic resonance imaging revealed a large retroperitoneal tumor adjacent to the aorta and the renal vessels. We judged that it was inoperable. Then we performed percutaneous needle biopsy of the tumor. Histopathological examination showed a malignant fibrous histiocytoma (MFH). Two cycles of systemic chemotherapy with pirarubicin, vincritine and cyclophosphamide were ineffective, then we tried concurrent cisplatin and radiation therapy. Chemoradiation therapy showed a marked decrease in the size of the tumor, and the patient also recovered from right lumbar pain without serious side effects. After chemoradiation therapy, we performed tumorectomy. However, we could not curatively resect the residual tumor. He suffered from repeated recurrence and metastases of MFH afterwards. We performed repeatedly concurrent cisplatin and radiation therapy for the recurrent and metastatic tumor sites, and chemoradiation therapy led to regression of the tumors every time. However he died from liver dysfunction due to multiple liver metastases in May 2005. Concurrent cisplatin and radiation therapy might be an effective treatment for unresectable MFH.