Liu Ping, Na Jia, Wang Ying, He Qun, Zhang Ying, Tang Xiuying, Zou Wanzhong
Department of Pathology, Peking University First Hospital, Beijing 100034, China.
Zhonghua Bing Li Xue Za Zhi. 2002 Jun;31(3):199-203.
To investigate the morphological features, immunohistochemical speciality of the gastrointestinal stromal tumors (GISTs), and its histogenesis as well.
The morphologic characteristics of GISTs were studied in 65 cases using light microscopy and 17 cases by electron microscopy. The expression of c-kit (CD117), CD34, vimentin, SMA, actin, desmin, S-100 and MBP were detected in all the cases with EnVision trade mark staining.
Among 65 cases of GISTs, 46 were spindle cell type, 6 epithelioid cell type and 13 mixture type, equivalent to 85.5% (65 of 76) of all of the mesenchymal tumors of gastrointestinal tract admitted in the same period. The epithelioid cell type tumors composed of mainly the epithelioid cells, predominantly short spindle, oval or round in pattern, with an overall eosinophilic cytoplasm by hematoxylin-eosin stain. Focal cytoplasmic vacuolization was often seen. Sometimes signet-ring like cells and cells with a clear cytoplasm were seen in the epithelioid stromal tumor. The tumor cells arranged in interlacing fascicles forming whorls or sometimes cell clusters. Electronic microscopy showed the presence of interdigitating cell processes, in some areas, synapse-like structure and numerous desmosome-like junctions as well as a few gap junctions and small round neurosecretory granules. There were also abundant intermediate filaments and thin filaments of actin-type with longitudinal condensations (dense bodies). All of the 65 stromal tumors were strongly positive for vimentin (100%), 61 out of 65 tumors positive for CD117 (c-kit) (93.8%) and 51 out of 65 positive for CD34 (78.5%). Some cases also expressed SMA, actin, S-100 and MBP.
GISTs were the most frequent mesenchymal tumor seen in the gastrointestinal tract. Under light microscope, the morphology of stromal tumors looks sometimes like a leiomyoma and Schwannoma. The application of immunohistochemical markers (particularly CD117 and CD34) and ultrastructural study are considered necessary for the differential diagnosis. GISTs may originate from the pluripotential precursor cells like the interstitial cells of Cajal.
探讨胃肠道间质瘤（GISTs）的形态学特征、免疫组化特性及其组织发生。
对65例GISTs进行光镜观察，17例进行电镜观察，研究其形态学特征。采用EnVision法检测所有病例中c-kit（CD117）、CD34、波形蛋白、平滑肌肌动蛋白（SMA）、肌动蛋白、结蛋白、S-100和髓磷脂碱性蛋白（MBP）的表达。
65例GISTs中，梭形细胞型46例，上皮样细胞型6例，混合型13例，占同期收治的全部胃肠道间叶性肿瘤的85.5%（76例中的65例）。上皮样细胞型肿瘤主要由上皮样细胞组成，形态多为短梭形、椭圆形或圆形，苏木精-伊红染色显示胞质呈嗜酸性。常可见局灶性胞质空泡化。在上皮样间质瘤中有时可见印戒样细胞和胞质清亮的细胞。肿瘤细胞呈交错束状排列，形成漩涡状，有时形成细胞簇。电镜显示有相互交错的细胞突起，某些区域有突触样结构、大量桥粒样连接以及少量缝隙连接和小圆形神经分泌颗粒。还有丰富的中间丝和肌动蛋白型细肌丝，伴有纵向凝聚（致密小体）。65例间质瘤中波形蛋白均呈强阳性（100%），65例中有61例CD117（c-kit）阳性（93.8%），65例中有51例CD34阳性（78.5%）。部分病例还表达SMA、肌动蛋白、S-100和MBP。
GISTs是胃肠道最常见的间叶性肿瘤。光镜下，间质瘤的形态有时类似平滑肌瘤和神经鞘瘤。免疫组化标记物（尤其是CD117和CD34）的应用及超微结构研究对鉴别诊断很有必要。GISTs可能起源于多能前体细胞，如Cajal间质细胞。
