54例胃肠道间质瘤的病理形态及免疫组化观察

目的 研究胃肠道间质瘤(GIST)的病理形态及免疫组织化学。方法 对GIST的形态进行光镜观察，用免疫组化En Vision两步法检测CD117(c—kit)、CD34、波形蛋白等6种抗体在肿瘤中的表达。结果 54例GIST，年龄35～85岁(平均58岁)，肿瘤细胞为梭形或上皮样，或两混合存在，排列成交织束状、栅栏状、漩涡状、巢团状及弥漫片状；梭形细胞为主型38例，上皮样细胞为主型5例，混合型11例；良性10例，潜在恶性14例，恶性30例；免疫组化CD117和CD34在GIST中显示弥漫强阳性，阳性率分别为94．4％、77．8％，Vimentin100％。结论 GIST好发于中老年人，肿瘤细胞形态、排列多样，HE镜下组织形态与平滑肌源性肿瘤及神经源性肿瘤难鉴别，CD117、CD34及Vimentin等一组抗体联合使用可协助诊断。

A pathomorphologic and immunohistochemical study on 54 cases of gastrointestinal stromal tumors

Objective To investigate the histopathological and immunohistochemical features of gastrointestinal stromal tumors(GIST).Methods Light microscope was used to study the morphologic characteristics of 54 cases of GIST,the expression of CD 117(c-kit),CD 34,vimentin,SMA,Desmin S-100protein were detected in all the cases with EnVision immunohistochemical method.Results 54 cases of GIST with their ages ranged 35 to 85 years(mean 58 years).The tumor cells were spindle, epithelioid or both in different proportion,arranged in interlacing fascides,palisading,whirling,alveolar and diffusing sheets.The tumors were composed of spindle cells(38 cases)or epithelioid cells(5 cases)or both (11 cases).Ten cases were benign,14 cases potentially malignant and 30 cases malignant. Immunohistochemically,CD 117 and CD 34 showed diffuse strong expression.The positive results accounted for 94.4% and 77.8% respsctively.Vimentin was positive in all cases.Conclusion GIST predominantly occurred in middle aged or older patients.The tumor cells had varied types and arrangements.Under light microscope,some of them were difficult to be differentiated from leiomyoma and schwannoma.Combined determination of the antibodies such as CD 117,CD 34 and vimentin is helpful for the differential diagnosis of GIST.