胃の悪性線維性組織球腫（malignant fibrous histiocytoma；MFH）の1例

Malignant Fibrous Histiocytoma (MFH) of the Stomach, Report of a Case

要旨　患者は64歳，女性．主訴は高度貧血，精査により胃体部に粘膜下腫瘍（SMT）を認め，中央部に粘膜欠損を起こした舌状隆起があり，大きさは4×4.5×7.5cmで，組織診断はmalignant fibrous histiocytoma（MFH）〔深達度ssβ，n(－)〕であった．胃原発のMFHは文献上6例にみられ，SMT，隆起性病変，潰瘍性病変を示したが，本例ではinflammatory fibroid polypに特徴的なSMTに舌状隆起を伴う陰茎亀頭様所見が認められた．MFHには腫瘍性出血による貧血例が多く，腫瘍性出血の病理学的形態を本例で検討した．MFHの報告例は予後不良であったが，本例は胃内に限局し良好な予後が期待される．

　A 66-year-old female was admitted because of severe anemia. X-ray and endoscopic examinations disclosed a submucosal tumor with a central protruded lesion on the posterior wall of the gastric body. Distal gastectomy was performed. The resected specimen revealed a unique protrusion, measuring 4×4.5×7.5 cm. Histologically, the lesion mainly occupied the submucosa and reached to the subserosa and was composed of atypical fibroblasts and atypical cells with bizarre giant nuclei, and diagnosed as malignant fibrous histiocytoma (MFH).

　Six cases of MFH were reviewed, and the gross findings were submucosal tumor, protruded lesion and ulcerated lesion. The gross finding of this case was glands penis-like appearance, and this unique gross finding is special for inflammatory fibroid polyps, but is also recognized in cases of MFH. Many cases of MFH showed clinically severe anemia due to bleeding from the tumor and, in this case, the cause of bleeding was discussed. The prognosis of MFH cases were poor due to the far-advanced nature of the tumors, but the prognosis in this case is good due to the fact that it was an intra-gastric tumor.