胃肠道间质瘤起源和分化的探讨

Study on the origin and differentiation of gastrointestinal stromal tumors

目的 探讨胃肠道间质瘤 (GIST)的起源或分化。方法 采用免疫组织化学EnVision和电镜的方法对GIST进行研究。结果 2 12例GISTCD117、CD34、α 平滑肌肌动蛋白 (SMA)、肌特异性肌动蛋白、结蛋白阳性率分别为 96 7% ,77 3% ,19 3% ,15 6 % ,1 9% ,其中S 10 0和PGP9 5的阳性反应分别为 16 3%及 12 3%。超微结构显示瘤细胞含丰富的线粒体 ,粗面内质网、游离核糖体和中间丝 ,有的细胞切面可见溶酶体和脂滴 ,高尔基复合体在核周分布 ,质膜处偶尔不规则地分布着一些微饮泡、密斑样结构及不连续的基板。部分病例细胞有多量细长指状突起 ,突起内有胞内成分如线粒体、粗面内质网延续 ,突起之间或突起与细胞膜有连接结构。细胞外间质内可见胶原原纤维或团丝样纤维。结论 GIST免疫表型及超微结构特征与胃肠壁成熟卡哈尔间质细胞相似 ,提示GIST可能是起源于幼稚间充质细胞向卡哈尔间质细胞分化的肿瘤 。

Objective To explore the origin and differentiation of gastrointestinal stromal tumors (GISTs) Methods Immunohistochemisty staining and electron microscopy were adopted Results In 212 cases of primary GISTs, the positive rates of CD117,CD34,α SMA,MSA,desmin,S 100,PGP9 5 were 96 7%,77 3%,19 3%,15 6%,1 9%,16 3%,and 12 3% respectively Among them, GISTs showed a diffuse and strong positivity for CD117 Electron microscopy of tumor cells demonstrated numerous mitochondria, prominent perinuclear Golgi complex, smooth and rough endoplasmical reticulum and intermediate filaments Irregular caveolae, dense plaque, incontinuous basal lamina were observed occasionally Cytoplasmic processes were often observed accompanying with local adhesion present between the processes or between the processes and the cell membrane Conclusions Data from both immunophenotype and electron microscopy suggest that GIST might originate from the mesenchymal cells, differentiating to be ICC afterwards, and possessing myoid characteristics in various extent