本文报告6例原发肠道恶性纤维组织细胞瘤,其中发生在小肠3例,回盲部、降结肠及乙状结肠各1例。镜下肿瘤主要由纤维母细胞样细胞和组织细胞样细胞构成,在二者之间有胖梭形过渡细胞。组织细胞样细胞可演变为泡沫细胞和多核、单核的瘤巨细胞,另见少量未分化间叶细胞。对其中2例进行了电镜超微结构的观察。 This article reports 6 cases of primary intestinal malignant fibrous histiocytoma, which occurred in 3 cases of small intestine, ileocecal, descending colon and sigmoid colon in 1 case. Microscopic tumors consist mainly of fibroblast-like cells and histiocytic cells, with fat shuttle-shaped transition cells between them. The histiocyte-like cells can evolve into foam cells and multinucleated, mononuclear giant tumor cells, and a small amount of undifferentiated mesenchymal cells. Two of them were observed for the ultrastructure of electron microscopy.