Fülöp Emoke, Marcu Simona, Milutin Doina, Borda Angela
Department of Histology, University of Medicine and Pharmacy of Targu Mures, Romania.
Rom J Morphol Embryol. 2009;50(3):319-26.
Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal tumors of the gastrointestinal tract. Major advances in their definition and classification and the understanding of their molecular mechanisms have recently been made. These advances have become a model of targeted therapy in oncology. The diagnosis of GISTs relies on histological arguments--proliferation of spindle-shaped cells in 70% of cases, of epithelioid cells in 20%, histological variants are rare--, and on immunohistochemical arguments--expression of CD117 in 95%, usually associated with CD34 expression in 70% of cases. Most GISTs are associated with molecular abnormalities in low target genes: KIT and PDGFRA. The differential diagnosis of GISTs includes the other mesenchymal tumors of the gastrointestinal tract, such as leiomyomas, leiomyosarcomas, schwannomas and intra-abdominal fibromatosis. The evaluation of the prognosis is essential and is based on a simple algorithm using two histoprognostic parameters, tumor size and mitotic index. The treatment of localized GISTs is surgical resection and that of advanced or unresecable GISTs is based on the use of targeted therapy, imatinib, which is a pharmacological antagonist of the c-kit protein. Proper understanding and utilization of the diagnostic criteria and classification of GISTs by pathologists are essential for good patient management.
胃肠道间质瘤（GISTs）是胃肠道最常见的间叶组织肿瘤。近年来，在其定义、分类以及分子机制的理解方面取得了重大进展。这些进展已成为肿瘤学中靶向治疗的典范。GISTs的诊断依赖于组织学依据——70%的病例为梭形细胞增殖，20%为上皮样细胞增殖，组织学变异罕见——以及免疫组化依据——95%的病例中CD117表达，通常70%的病例伴有CD34表达。大多数GISTs与低靶点基因KIT和PDGFRA的分子异常有关。GISTs的鉴别诊断包括胃肠道的其他间叶组织肿瘤，如平滑肌瘤、平滑肌肉瘤、神经鞘瘤和腹腔内纤维瘤病。预后评估至关重要，基于一个使用肿瘤大小和有丝分裂指数这两个组织预后参数的简单算法。局限性GISTs的治疗是手术切除，晚期或不可切除GISTs的治疗基于使用靶向治疗药物伊马替尼，它是c-kit蛋白的药理学拮抗剂。病理学家正确理解和运用GISTs的诊断标准及分类对于良好的患者管理至关重要。
