Sarlomo-Rikala M, Kovatich A J, Barusevicius A, Miettinen M
Department of Pathology, Haartman Institute, University of Helsinki, Finland.
Mod Pathol. 1998 Aug;11(8):728-34.
Gastrointestinal stromal tumors (GISTs) represent a distinct and the most important subset of mesenchymal tumors of the GI tract. These tumors are both phenotypically and genotypically different from true leiomyomas and usually express CD34, a hematopoietic progenitor cell antigen. CD34, however, is also present in a wide variety of fibroblastic and endothelial cell tumors. In this immunohistochemical study of CD117, we evaluated 85 cases of GIST and more than 150 other mesenchymal tumors, including leiomyomas and schwannomas. CD117, the c-kit proto-oncogene product, is expressed in subsets of hematopoietic stem cells, mast cells, melanocytes, and interstitial cells of Cajal of the GI tract. CD117 was almost always (85%) expressed in both benign and malignant GISTs. CD117 was observed both in the spindle cell and epithelioid subtypes of GISTs in all locations. In addition to reacting with the CD34-positive GISTs, CD117 was positive in some CD34-negative cases. Approximately one-third of GISTs coexpressed CD117 and smooth muscle actins. In contrast, true leiomyomas (desmin and actin-positive) and schwannomas in both GI and peripheral locations were consistently negative for CD117. Solitary fibrous tumors and Kaposi's sarcomas, which are typically CD34 positive, were consistently CD117 negative. Among the CD34-positive tumors that showed occasional CD117 reactivity were dermatofibrosarcoma protuberans (1 of 7) and hemangiopericytoma (2 of 10). Other mesenchymal tumors that were variably CD 117 positive included clear cell sarcoma (7 of 15), metastatic melanoma (9 of 25), and malignant fibrous histiocytoma (1 of 20). These results indicate that CD117 is a specific marker for GIST among tumors that occur in the GI tract and adjacent regions. CD117 expression also separates GISTs from true leiomyomas and gastric schwannomas.
胃肠道间质瘤（GISTs）是胃肠道间叶性肿瘤中一个独特且最重要的亚型。这些肿瘤在表型和基因型上均与真正的平滑肌瘤不同，通常表达CD34，一种造血祖细胞抗原。然而，CD34也存在于多种成纤维细胞和内皮细胞瘤中。在这项关于CD117的免疫组织化学研究中，我们评估了85例GIST以及150多例其他间叶性肿瘤，包括平滑肌瘤和神经鞘瘤。CD117是c-kit原癌基因产物，在造血干细胞、肥大细胞、黑素细胞以及胃肠道的Cajal间质细胞亚群中表达。CD117在良性和恶性GIST中几乎总是（85%）表达。在所有部位的GIST的梭形细胞和上皮样亚型中均观察到CD117表达。除了与CD34阳性的GIST反应外，CD117在一些CD34阴性病例中也呈阳性。大约三分之一的GIST共表达CD117和平滑肌肌动蛋白。相比之下，真正的平滑肌瘤（结蛋白和肌动蛋白阳性）以及胃肠道和外周部位的神经鞘瘤CD117始终为阴性。通常CD34阳性的孤立性纤维瘤和卡波西肉瘤CD117始终为阴性。在偶尔显示CD117反应性的CD34阳性肿瘤中，有隆突性皮肤纤维肉瘤（7例中的1例）和血管外皮细胞瘤（10例中的2例）。其他CD117呈不同程度阳性的间叶性肿瘤包括透明细胞肉瘤（15例中的7例）、转移性黑色素瘤（25例中的9例）和恶性纤维组织细胞瘤（20例中的1例）。这些结果表明，在发生于胃肠道及邻近区域的肿瘤中，CD117是GIST的特异性标志物。CD117表达也将GIST与真正的平滑肌瘤和胃神经鞘瘤区分开来。
