後腹膜悪性線維性組織球腫の検討

Abstract

1985年～2005年に診断した悪性線維性組織球腫(MFH;Malignant fibrous histiocytoma)7例(男5例女2例、平均年齢58歳)について検討した。主訴の腹部背部痛は全例の6割で認められ、2例に発熱倦怠感等全身症状を伴った。腫瘍発生部位は後腹膜腔以外に精索周囲組織もあり、腫瘍長径平均11.5cmで、臨床経過は観察期間が中央値5ヵ月、6例で治療目的に腫瘍摘出術を実施した。摘出術実施6例中、術後局所再発は5例、再発までの期間は平均1.5ヵ月であり、手術以外の治療を放射線治療を4例で実施し、うち2例で再発、転移巣の治療を行った。化学治療は1例に実施し、mesna、adriamycin、ifosfamide、dacarbazine(MAID)を用いたが、開始後局所再発で死亡した。死亡した5例の生存期間は平均3.5ヵ月で、現在も生存中の2例中1例が左精索原発のMFHであった。また、1例は右腎被膜由来のMFHで再発を繰り返していたが、その都度完全摘除が可能であった。

The definition of malignant fibrous histiocytoma (MFH) was modified and simplified in the new WHO-Soft Tissue and Bone Tumor Classification published in 2002. We reviewed the clinical courses of 7 patients with MFH of the retroperitoneum treated in our hospital from 1985 to 2005 and reexamined their pathological diagnoses according to the new classification. All pathological specimens were reviewed again by an expert pathologist (TH) and were confirmed as MFH. Median follow-up was 5 months (0.5 to 44 months). Five patients were diagnosed as having the pleomorphic type, and 2, the inflammatory type. The tumor was located in the retroperitoneal space in 6 patients and around the left spermatic cord in 1. Radical surgery was the primary treatment for 6 patients. The disease recurred locally in 5 patients and distant metastasis developed in 3. The lung and liver were the principal locations of distant metastases. The 2-year disease-specific survival rate was 30% and 2 patients have been alive for more than 3 years. Our experience and those of others reported in the literature suggested that the factors for long-term survival in MFH are pleomorphic-type histology, superficial location, small tumor size and intensive wide excision, although most patients with MFH might have a poor prognosis. Because the tumor size of MFH tended to be large, especially that in the retroperitoneal cavity, wide excision with sufficient tumor-free margin is hard to guarantee.