消化道间叶源性肿瘤49例临床病理和免疫组化研究

Gastrointestinal mesenchymal tumors:clinicopathologic and immunohistochemical studies of 49 cases

目的 探讨消化道间叶源性肿瘤的临床病理学特点和免疫组化表型。方法 对 4 9例消化道间叶源性肿瘤进行临床病理分析 ,并行CD117、CD34、actin、desmin、S 10 0和ALKl等标记和分类 ,研究GIMT的鉴别诊断。结果 4 9例消化道间叶源性肿瘤中 ,有 36例胃肠道间质瘤 ,主要由梭形细胞组成 ,部分病例可呈上皮样 ,瘤细胞排列呈多样化 ,主要表达CD117和CD34;4例平滑肌瘤 ,由嗜伊红梭形细胞组成 ,瘤细胞弥漫强阳性表达α SMA、MSA和 /或desmin ;2例神经鞘瘤 ,形态上与发生于周围软组织的神经鞘瘤有所不同 ,瘤细胞表达S 10 0、PGP9 5和GFAP等抗体 ;炎性纤维性息肉、小肠纤维瘤病和炎性肌纤维母细胞瘤各 1例 ,均表达vimentin ,灶性表达actin和desmin ,1例炎性肌纤维母细胞瘤尚表达ALK1;余 4例难以分类。结论 消化道间叶源性肿瘤中以胃肠道间质瘤最为多见 ,而真正的平滑肌 (肉 )瘤及神经源性肿瘤均非常少见。

Objective To study the clinical, pathological and immunohistochemical characteristics of gastrointestinal mesenchymal tumors (GIMTs). Methods The clinical and pathological features of 49 cases of GIMT were reviewed, and immunohistochemical study was performed by using a panel of antibodies,including CD117, CD34, actins, desmin, S-100 protein and ALK1. Results Among 49 cases of GIMTs, 36 cases were gastrointestinal stromal tumors. While most GISTs were composed of spindle-shaped cells, some cases showed a predominance of epithelioid cells. The arrangement of neoplastic cells varied greatly among cases. They were positive for CD 117 and/or CD34. 4 cases were leiomyomas, similar to their peripheral soft tissue or uterus counterparts.They showed a diffuse and strong staining of α-SMA, MSA and desmin. 2 cases of schwannomas were identified. Their morphologic features differed from those of peripheral ones. They were positive for S-100 protein, PGP9 5, and GFAP. There was 1 case each of inflammatory fibrous polyp, mesentery fibromatosis and inflammatory myofroblastic tumor (IMT). These 3 cases showed expression of vimentin, focal staining of actins and/or desmin. Additionally, the IMT case expressed anaplastic lymphoma kinase 1 (ALK1). The remaining 4 cases were unclassified. Conclusion GISTs are the most common mesenchymal tumors in gastrointestinal tract. In contrast, bona fide leimyoma, leiomyosarcoma or neural tumors are extremely rare. Using a panel of antibodies is helpful in the differentiatial diagnosis of GIMTs.