与胃间质瘤恶性程度相关的临床病理和免疫组化研究

目的：探讨胃间质瘤的临床表现，病理组织形态学和免疫组织化学特点及恶性程度指标。方法：用CD117、CD34、SMA、S-100、ki67五种抗体，通过免疫组织化学SABC法，确诊99例胃间质瘤，并结合临床、病理及随访资料，对其生物学行为进行分析。结果：本组胃间质瘤，CD117和CD34多为弥漫强阳性，阳性率分别为90．9％、74．7％、SMA、S-100呈片状或局灶阳性，阳性率分别为15．2％、5．1％，ki67标记指数为5．1％。潜在恶性52例，恶性47例，平均随访期为5年，各组之间瘤体直径大于5cm，核分裂象大于5／50HPF，差异有显著性意义。单因素分析瘤体大小，恶性程度。核分裂象，完整切除均与生存率有关。多因素分析只有完整切除为决定生存率有意义指标。结论：胃间质瘤免疫组织化学特征为CD117、CD34阳性，瘤体直径大于5cm，核分裂象大于5／50HPF可作为高度恶性参考指标。

Malignancy-related clinicopathological and immunohistochemical features of gastric stromal tumors

Objective: To study the clinical manifestations, pathologic morphology, and immunohistochemical features of gastric stromal tumors and to explore the reference indexes for malignancy. Methods: Ninety-nine cases of primary gastric stro-mal tumors were distinguished from a group of gastrointestinal mesenchymal tumors by immunhistochemical SABC method using 5 antibodies such as CD117, CD34, SMA, S-100, and ki67. Their biological behaviors were analyzed and associated with the clinicopathological features and the follow-up data. Results: Immunohistochemically, CD117 and CD34 showed diffuse strong positive expression. The positive rates were 90. 9% and 74. 7% , respectively. SMA and S-100 showed focal positive expression. The positive rates were 15. 2% and 5. 1% , respectively. ki67 labeling index was 5. 1%. Fifty-two cases were potentially malignant and forty seven cases were malignant. The average follow-up period was 5 years. If the tumor size was >5 cm in diameter and mitotic activity was > 5/50HPF, the difference was significant. Univariate analysis showed that tumor size, malignant degree, mitotic count, and complete resection correlated with survival rate. Multivariate analysis showed that only the complete resection was a useful index to determine the survival rate. Conclusion: Gastric stromal tumors show CD117 and CD34-positive staining. Tumor size >5 cm in diameter and mitotic activity >5/50HPF could be used as useful reference indexes for malignancy.