66例胃肠道间叶源性肿瘤临床和病理特征分析

Clinical and Pathological Features of Gastrointestinal Mesenchymal Tumor: An Analysis of 66 Cases

背景胃肠道间质瘤(GISTs)是发生于胃肠道的一种特殊类型的间叶源性肿瘤,具有从良性到显著恶性的广谱生物学行为,其特征性分子学改变是c鄄kit基因突变,其他胃肠道间叶源性肿瘤(GIMTs)则无此特征。因此,有必要正确认识和诊断GISTs,以将其与其他GIMTs区分开来。目的加强对GISTs的认识,以正确诊断GISTs。方法总结1980～2004年间杨浦区中心医院GIMTs病例的病史资料,选用CD117、CD34、α鄄平滑肌抗体(SMA)、结蛋白(desmin)和S鄄100这一组抗体对GIMTs进行标记、分类,重点分析GISTs的临床、病理和免疫组化特征。结果本组66例GIMTs中56例为GISTs(84.8%),肿瘤多发生于胃和小肠(91.1%),良性和交界性29例,恶性27例,临床表现主要为中上腹不适、腹部包块和消化道出血。间质瘤组织由梭形细胞和上皮样细胞组成,CD117和CD34呈弥漫性强表达,阳性率分别为89.3%和66.1%,部分病例局灶表达α鄄SMA和S鄄100,阳性率分别为30.4%和7.1%,desmin表达均阴性。平滑肌瘤3例,均弥漫性强表达α鄄SMA和desmin,余阴性。神经鞘瘤4例,均弥漫性表达S鄄100,余阴性。其他少见或难以分类的肿瘤3例。结论本组GIMTs中以GISTs最为多见,平滑肌瘤和神经鞘瘤少见。临床工作中应加强对GISTs临床和病理特征的认识,以提高其诊断和治疗水平。

Background: Gastrointestinal stromal tumors (GISTs) are specific gastrointestinal mesenchymal tumors (GIMTs) that can occur in the entire gastrointestinal tract. These tumors have a wide clinical spectrum from benign, small, incidentally detected nodules to frankly malignant tumors. The understanding of the molecular pathogenesis, presence of c-kit gene mutation, make it necessary to recognize and diagnose these tumors clinically and separate them from other GIMTs. Aims: To make a correct diagnosis of GISTs. Methods: The case history of all GIMTs patients from 1980-2004 in the Central Hospital of Yangpu District were reviewed and summarized retrospectively, and immunohistochemical markers, a panel of antibodies as CD117, CD34, α-smooth muscle antibody (SMA), desmin and S-100 were labeled to reclassify the GIMTs. The clinical, pathological and immunohistochemical features were analyzed, in particular, the GISTs. Results: Among the 66 GIMTs enrolled in the present study, there were 56 GISTs (84.8%). Most of the stromal tumors were located in the stomach and the small intestine (91.1%), 29 were benign and borderline, and 27 were malignant. The main manifestations of GISTs were epigastric discomfort, abdominal mass and gastrointestinal bleeding. The tumor tissues consisted of fusiform cells and epithelioid cells, the CD117 and CD34 were diffusely and strongly expressed as shown by immunohistochemistry, the positivity rates were 89.3% and 66.1%, respectively; α-SMA and S-100 showed focal expression, the positivity rates were 30.4% and 7.1%, respectively, and desmin were negative in all. In 3 cases of leiomyoma, α-SMA and desmin were diffusely and strongly expressed whereas the other markers were negative. In 4 cases of neurilemmoma, only diffuse expression of S-100 was observed. Another 3 cases of GIMTs were miscellaneous tumors. Conclusions: In the present study, GISTs is the most common tumor among the GIMTs, whereas leiomyoma and neurilemmoma are less common. In clinical practice, we have to pay more attention to the clinical and pathological features of GISTs to promote its diagnostic and treatment level.