胃肠道间质肿瘤组织发生的探讨

目的探讨胃肠道间质肿瘤（ｇａｓｔｒｏｉｎｔｅｓｔｉｎａｌｓｔｒｏｍａｌｔｕｍｏｒ，ＧＩＳＴ）的组织发生。方法对３６例ＧＩＳＴ进行组织学、组织化学及免疫组织化学观察。结果胃和大肠间质肿瘤呈间叶细胞表型，但光镜下观察到在１５例发生于小肠的梭形细胞肿瘤中，瘤细胞之间存在着嗜酸性小体即丝团样纤维（ｓｋｅｉｎｏｉｄｆｉｂｅｒ，ＳＦ），Ｍａｓｓｏｎ三色染色呈蓝色，ＰＡＳ呈强阳性；免疫组化染色显示Ｓ－１００蛋白阳性率为４４．４４％，ｄｅｓｍｉｎ阳性率为８．３３％，瘤细胞的免疫表达与其分化程度无关。结论胃和大肠的间质肿瘤免疫表型复杂，提示其起源与原始间叶细胞有关，而小肠间质肿瘤大多数为神经源性肿瘤。可能起源于肠壁内在神经丛的神经膜细胞或来自小肠的自律神经。

A study on histogenesis of gastrointestinal stromal tumors

OBJECTIVE: The purpose of this study was to consider the histogenesis of gastrointestinal stromal tumors (GIST). METHOD: 36 cases of GIST were studied by light microscopy, histochemical and immunohistochemical techniques. RESULTS: In 15 cases of small intestine spindle cell tumors, various sized eosinophilic globules were observed between the tumor cells and were designated as skeinoid fibers, which stained blue with Masson's trichrome and strongly PAS-positive. The positive rate by immunohistochemical methods for S-100 protein and desmin were 44.44% and 8.33% respectively. The immunoexpression of tumor cells was unrelated to their differentiation. CONCLUSION: Complex immunophenotypes of GIST suggest primitive mesenchymal origin, and small intestine stromal tumors (SIST) are mostly neurogenic which may have been derived from neurilemmal cells or autonomous nerve tissue of the small intestine.