胃肠道及胃肠道外间质瘤的临床病理及免疫组化分析

目的:研究胃肠道及胃肠道外间质瘤的临床病理及免疫组化特点。方法:应用光学显微镜观察20例胃肠道及胃肠道外间质瘤的形态特征,用免疫组化SP法检测CD117、CD34、Vimentin、SMA、desmin及S-100等6种抗体的表达情况。结果:20例间质瘤中,女性11例,男性9例,平均年龄59·82岁(27~80岁)。发生部位:胃8例(40%),小肠4例(20%),大肠2例(10%),食管1例(5%),肠系膜4例(20%),大网膜1例(5%)。肿瘤镜下主要由梭形和上皮样细胞组成,有栅栏状、交叉束状、漩涡状及巢状等多种排列。CD117、CD34、Vimentin、SMA、desmin及S-100表达阳性率分别为95%(19/20),75%(15/20),100%(20/20),40%(8/20),5%(1/20)及25%(5/20)。临床症状以腹部包块、腹部不适及消化道出血为主。良性3例(3/20),潜在恶性4例(4/20),恶性13例(13/20)。恶性间质瘤中的核分裂>5/50HPF、肿瘤细胞坏死及细胞密集比良性和低度恶性者常见(P<0·05)。结论:间质瘤多发生于老年人,无性别差异,胃肠道是其好发部位,细胞排列多样,具有多向分化能力,免疫组化证实部分GIST具有不完全的平滑肌、神经单向或双向分化特征。核分裂>5/50HPF、肿瘤细胞坏死及细胞密集是重要的恶性指征。CD117及CD34是其较特异及敏感的抗体,免疫组化在间质瘤的诊断及鉴别诊断中起重要作用。

To analysis the clinicopathologic and immunohistochemical features of gastrointestinal stromal tumor and external gastrointestinal stromal tumor

Objective:To study the clinicopathologic and immunohistochemical characteristics of gastrointestinal stromal tumors(GIST) and external gastrointestinal stromal tumors(EGIST).Methods:The morphologic features in 20 cases of GISTs and EGISTs were observed under light microscopy. The expressions of CD117,CD34,Vimentin,SMA,desmin and S-100 were detected by immunohisto-chemical SP method.Results:In 20 cases of GISTs,age mean 59.82 years(range from 27 to 80 years),female 11 cases and male 9 cases. The tumors were situated in stomach(8 cases),in small intestine(4 cases),in large intestine(2 cases),in esophagus(one case),in mesenterium(4 case) and in omemtum(one case). The tumors were mainly composed of spindle cells and epithelioid cells,arranged in pallisading,interlacing fasicles,whirling,cellular clusters,et al. The positive rates of CD117,CD34,Vimentin,SMA,desmin and S-100 in 20 cases were 95%(19/20),75%(15/20),100%(20/20),40%(8/20),5%(1/20) and 25%(5/20) respectively. The most common symptoms were abdomen mass,discomfort and gastrointestinal hemorrhage. Three cases were benign,four cases potential malignant and 13 cases malignant. Mitotic activity over 5/50 HPF,tumor cell necrosis and high tumor cellularity had significant differences among three groups.Conclusion:GIST predominantly occurred in older patients. There were not different between female and male cases. GIST seems to occur most frequently at gastrointestinal tract. The tumor cells had varied arrangements and multiple differentiated characteristic. Immunostaining suggested that only some of the GISTs showed partial differentiation toward smooth muscle,neuron or both. Mitotic activity over 5/50 HPF,high tumor cellularity and tumor necrosis were the helpful parameters for judgement of malignancy. CD117 and CD34 were the more specific and sensitive antibody in diagnosis of GISTs. Immunohistochemisty plays an important role in the pathological diagnosis and differential diagnosis of GISTs.