胃肠道间质瘤的组织病理学和免疫组织化学特点

Histopathological and immunohistochemical features of gastrointestinal stromal tumor

目的:探讨胃肠道间质瘤(GIST)的组织病理学和免疫组织化学特点.方法:用CD117、CD34、SMA、Desmin、S-100蛋白质抗体通过免疫组织化学SP法对22例原发性GIST患者进行组织病理学和免疫组织化学检测.结果:GIST基本组织形态为梭形细胞和上皮样细胞,可以伴有囊性变、黏液变、出血及坏死.核分裂像大于5/50HPF的5例中肿瘤直径均大于或等于5 cm,其中4例伴有囊性变、出血或坏死,1例伴有黏液样变.2例核分裂像在2～5/50HPF者均为上皮样细胞型,其中1例伴有黏液样变,肿瘤直径均2～4 cm.免疫组化染色CD17和CD34多为弥漫强阳性,阳性率分别为95.5%和68.2%,Desmin不表达,S-100蛋白质和SMA不表达或者呈灶状阳性.结论:GIST肿瘤细胞形态多变和排列方式多样,免疫组织化学染色为CD117、CDa4阳性,Desmin阴性,S-100蛋白和SMA不表达或者呈灶状阳性;肿瘤细胞直径大于或等于5 cm、核分裂像大于5/50HPF、有出血或坏死可作为判断肿瘤恶性程度的参考指标.

Objective To explore the histopathological and immunohistochemical features of gastrointestinal stromal tumor （GIST）. Methods Histopathological and immunohistochemical detections were peformed in 22 cases of primary GIST with CD117, CD34, Desmin, SMA, S-100 protein by SP methods. Results The primary cell morphology consisted of spindle shaped cells and epithelioid cells. Cystification, mucification, hemorrhage or necrosis presented at the same time. The mitotic count was higher than 5/50HPF in 5 cases in which the diameters of tumor were above or equal to 5 cm. Cystification, hemorrage or necrosis were found in 4 cases and mucification in 1 case. The mitotic count was 2-5/50HPF in 2 cases which were epithelioid cell and tumor diameter were 2-4 cm with mucification in 1 case. CD117 and CD34 showed diffuse strong expression with immunohistochemical staining, the positive rates were 95. 5% and 68.2%, respectively. Desmin almost never presented, S-100 protein and SMA focally presented or were absent. Conclusion The morphology of GIST consist of various kinds of cell types and different arrangements. Immunohistochemical staining is positive for CD117 and CD34, negative for desmin, focally positive or absent for S-100 protein and SMA. The tumor＇s diameters are above or equal to 5 cm, mitotic count is over 5/50HPF, hemorrhage or necrosis might be helpful to identify tumors with malignant potential.