上皮样胃肠道间质瘤43例临床病理学特征分析

目的探讨上皮样胃肠道间质瘤(gastrointestinal stromal tumors,GIST)的临床病理学特征。方法对43例上皮样GIST患者进行常规病理、免疫组化标记。结果本组上皮样GIST患者的男女之比为1.7∶1,平均年龄60岁。肿瘤以胃、腹盆腔为多见,其中复发6例,发生肝转移4例。镜下肿瘤细胞以圆形、卵圆形或短梭形为主,胞浆丰富透明或嗜酸,可见透明空泡状及印戒样细胞。可形成微囊状结构,成片状、巢状,可见纤细或粗大的纤维分隔,部分可见腺管样结构。6例复发病例中有2例原发为梭形细胞型(余不详)。CD117、CD34、DOG1的阳性率分别为79.07%,73.81%,84.85%,3例CD117阴性病例DOG1阳性表达。有4例CD117、DOG1均阴性,CD34却阳性表达。结论上皮样GIST具有上皮样肿瘤的形态学特点,易发生误诊,应予以仔细鉴别。梭形细胞型GIST复发,可发生上皮样的改变。在上皮样GIST中DOG1的阳性率高于CD117,CD117、CD34、DOG1联合应用可提高诊断准确率。

Clinicopathological features in 43 cases of patients with epithelioid gastrointestinal stromal tumors

Objective To investigate clinicopathological features of epithelioid gastrointestinal stromal tumors （gastrointestinal stromal tumors,GIST）.Methods By routine pathological and immunohistochemical markers,43 epithelioid GIST cases were observed and clinicopathological features was discussed and analyzed. Results The ratio of male to female was 1.7∶1. The average age was 60 years old.Most were located at stomach,abdominal and pelvic.6 cases were recurrence and 4 cases metastasized to the liver among all cases.Microscopically, the tumor mainly consisted of round,oval or short spindle cells with abundant cytoplasm which were transparent or eosinophilic. In some cases transparent vacuoles cells and signet ring-like cells were observed,which were separated by slender or thick fiber, could formed into microcapsule structure,sheets or nests. Duct-like structure could be found in some cases. 2 cases of primary GIST were in spindle cell type in the six recurrent cases （Others was unknown）. The tumors were positive for CD117 79.07%, CD34 73.81%, DOG1 84.85%. Three cases of CD117 negative expressed DOG1 positive. It was worth mentioning that CD117 and DOG1 were negative,while CD34 was positive in four cases.Conclusion Epithelioid GIST possessed characteristics of epithelioid tumors in morphology,so it was easy misdiagnosed and should be identified.When GIST of Spindle cell recurred,it would have occurrence of epithelioid change.The positive rate of DOG1 of epithelioid GIST was higher than that of CD117. However,the difference was not statistically significant.Morphological features of epithelioid GIST with epithelioid tumor, was prone to misdiagnosis, should be careful to identify. Spindle cell type GIST recurred, epithelioid changes could occurred. The positive rate of DOG1 in epithelioid GIST was higher than that of CD117. The combination of CD117,CD34,DOG1 could improve the accuracy rate of diagnosis.