胃肠间质瘤的临床病理及其免疫组织化学探讨

A Clinicopathologic and Immunohistochemical Study of Gastrointestinal Stromal Tumors(A 56 Cases Report)

目的:探讨胃肠间质瘤(GIST)的诊断标准、良恶性参考指标和预后因素。方法:分析GIST的临床表现、病理组织形态,用免疫组织化学Envision法检测其CD117、CD34、a-SMA、S-100蛋白的表达状况,并结合随访资料,分析其生物学行为。结果:本组GIST平均年龄57.5岁。最常见症状为腹痛和消化道出血。肿瘤境界清楚,切面灰白,部分区可见出血、坏死、囊性变等继发性改变。镜下:梭形细胞型48例,上皮样细胞型5例,梭形/上皮样细胞混合型3例。CD117和CD34多弥漫强阳性,阳性率为89.29%、80.36%。a-SMA、S-100阳性率分别为28.57%、25%。56例GIST中,良性9例,交界性15例,恶性32例。良性与交界性病例随访24例均健在;恶性病例随访24例,18例无瘤生存,6例复发与转移。结论:GIST好发于中老年,瘤细胞形态多变,排列结构多样。免疫组织化学特征CD117、CD34阳性。肿瘤临床和病理形态、CD117和CD34表达是诊断GIST的要点。肿瘤直径>5cm,核分裂相>5/50HPF可作为良恶性参考指标。肿瘤性坏死、核分裂相>5/50HPF及肿瘤大小是预后的重要因素。

Objective：To investigate the diagnostic crietria of gastrointestinal stromal tumors（GIST） and the reference parame ters for malignancy and to explore the prognostic factors. Methods： Themorphologic of 56 cases GIST was observated. The expression of CD117,CD34,a SMA and S-100 were detected by the immunohistochemisty method with Envision. Their biologic behaviors were analyzed by including their follow-up data. Results： The average age was 57.5 years. The most common symptoms were vague pain and GI bleeding. Grossly of their middle were grayish. Some of them were of soft consistency often with hemorrhage,cystification or necrosis. Microscopically,the tumors were composed of spindle cells 48 cases or epithelioid cells 5 cases and of both cells 3 cases. CD117 and CD34 showed diffuse strong expression, the positive rates were 89.29% and 80. 36% ,respectively. a SMA, S-100 showed low expression, the positive rates were 28.57%o and 25%, respectively. 9 cases were benign, 15 cases borderline and 32 cases malignant. Follow up of 24 cases with benign and borderline tumors found patients alive without tumor. In the malignant group of cases, 18 cases were alive without tumor, 6 cases developed recurrence or metastasis. Conclusion： GIST predominantly occur in middle ages or old patients. The tumors have varied cell types and different ar rangements,the immunohistochemical characters are positive for CD117 and CD34. morphologie and coexpressior of tumor are the diagnostic criteria of GIST over 5cm in diametor and mitotic activity over 5/50HPF but lessthan 10/50HPF might be the potential parameters. Malignancy of tumors,over 5/50HPF and the sizes of the tumors is the important prognostic factors.