目的 探讨不同临床分期和病理分型的胸腺瘤生物学特性、预后及术后治疗手段。方法 收集手术切除胸腺瘤标本109例， 应用Masaoka和WHO标准分别进行临床分期和病理分型， 采用上皮膜抗原( epithelial membrane antigen， EMA)和Ki67两组单克隆抗体行免疫组化染色， 观察两组抗体在不同临床分期和病理分型胸腺瘤中的表达状况， 进行统计分析。结果 不同临床分期和病理分型胸腺瘤患者， EMA阴性和阳性率表达， 差异均无统计学意义， 但从Ⅱb期和B₂型开始， 表达强度逐渐增强， 与Ⅰ期和Ⅱa期及A、AB和B₁型相比， 差异有统计学意义( P<0.01)。Ki67指数从Ⅱb期和B₂型开始， Ⅲ级和Ⅳ级明显增加， 与Ⅰ期和Ⅱa期及A、AB和B₁型相比， 差异有统计学意义( P<0.01)。 结论 Masaoka分期Ⅱb期， WHO分型B₂型开始以上的胸腺瘤可能更具有侵袭性或恶性倾向， 术后应采用放疗或化疗等辅助治疗措施。

Objective To study biological characteristics, prognosis and postoperative treatment in different clinical stages and pathologic types of thymoma. Methods Expressions of epithelial membrane antigen ( EMA) and Ki67 monoclonal antibody were detected by immunohistochemistry in thymoma resection specimens of 109 cases. The expression level of these antibody was respectively observed in different Masaoka stages and WHO pathological classification of thymoma, and statistical analysis was carried out. Results In different clinical stage and pathological type patients with thymoma, EMA negative or positive expression rate had no statistically significant difference, but from clinical stage Ⅱb and B₂ pathologic type, the expression intensity was gradually increased, and had the extremely significant difference ( P<0.01), differently compared with stage Ⅰ, stage Ⅱa, A type, AB type and B₁ type. Since stage Ⅱb and B₂ type, level Ⅲ and Ⅳ of Ki67 index increased significantly, and had very significant differonce ( P<0.01), compared with stage Ⅰ and Ⅱa and A, AB and type B₁. Conclusions The thymoma from Masaoka stage Ⅱb and the WHO classification type B₂ may have aggressive or malignant tendency, so postoperative adjuvant treatment measures should be taken.