消化道平滑肌肿瘤190例病理学观察

目的：研究消化道平滑肌瘤(LA)和平滑肌肉瘤(LS)的鉴别。方法：采用肉眼，HE染色、特殊染色、免疫组织化学及电镜技术对消化道190例LA和LS进行形态学观察。结果：LA平均直径3.3cm，表面光滑，质地坚韧，壁间型、腔内型多见。细胞富裕1-2级多，细胞形态梭形或上皮样，细胞分化程度高，细胞核多为细棒状，肥胖形，核分裂计数平均0.47/25 HPF，无核分裂占75％。LS平均直径8.6cm，质地鱼肉样，哑铃型多见。细胞富裕2-3级多，细胞多形性，细胞核多不规则，巨核、多核，核分裂平均计数20/25 HPF，细胞分化程度低。应用特殊染色、免疫组化染色和电镜技术鉴别组织来源。结论：核分裂计数是诊断LA和分辨低度、中度、高度恶性LS的主要依据，免疫组化和电镜技术也是确定平滑肌组织来源的重要手段。

Pathological observation of 190 cases of smooth muscle tumor in gastrointestinal tract

Objective: To study the differentiation between leiomyoma (LA) and leiomyosarcoma (LS). Methods: One hundred and ninety cases of LA and LS in gastrointestinal tract were investigated by gross, HE staining, special staining, immunohistochemical staining and electric microscopy. Results: The average value of the diameter of LA was 3.3 cm. Tumor surfaces were smooth. Cut section showed hard texture. Interwall and intracavity type were most commonly found.Density of tumor cells reached 1-2 grade. Tumor cells displayed well-differentiation.Nuclei of tumor cells appeared usually to be thin-stick shape or plump-shape. Mean count of mitotic figure was 0.47/25 HPF. Mitotic activity was not observed in 75%of cases. The average value of the diameter of LS was 8.6 cm. The texture was flesh. The dumbbell-shape was commonly seen. Density of tumor cells reached 2-3 grade. Tumor cells were various in shape, and they displayed less-differentiation. Nuclei of tumor cells were irregular in shape or present with giant nuclei or multinuclei. Mean counting of mitotic figure was 20/25 HPF. Specific staining, immunohistochemical staining and electric microscopy were mainly used for determining the origin of tumor cells.Conclusion: Nine items of diagnostic criteria of LA and LS were proposed, in which mitotic figure counting was the basis of diagnosis of LA and the basis of differentiation of low-degree, moderate-degree and high-degree malignant LS. Immunohistochemical staining and electric microscopy are helpful for determining the origin of smooth muscle tumor.