目的探讨子宫内膜样腺癌及癌前病变组织中PTEN蛋白表达的相互关系及意义。方法采用免疫组化SP法检测正常子宫内膜、内膜增生、非典型性增生和子宫内膜样腺癌组织中PTEN蛋白的表达。结果非典型性增生和子宫内膜样腺癌组中PTEN蛋白阳性表达率分别为50·0%和45·5%,两组中PTEN阳性表达均显著低于正常子宫内膜和子宫内膜增生组(P<0·001)。癌组中PTEN阳性表达的缺失与组织学分级(P<0·002)、肌层浸润深度或伴有转移(P<0·03)及临床分期有关(P<0·002)。结论PTEN表达缺失涉及了子宫内膜样腺癌的发生、发展过程,PTEN蛋白的检测可作为子宫内膜样腺癌的早期诊断、判断肿瘤生物学行为的生物学指标。 Objective To investigate the relationship between PTEN protein expression in endometrioid adenocarcinoma and precancerous lesions. Methods The expression of PTEN protein in normal endometrium, endometrial hyperplasia, atypical hyperplasia and endometrioid adenocarcinoma was detected by immunohistochemical SP method. Results The positive expression rate of PTEN protein in atypical hyperplasia and endometrioid adenocarcinoma was 50.0% and 45.5%, respectively. The positive expression of PTEN in both groups was significantly lower than that in normal endometrium and endometrial hyperplasia Group (P <0.001). The loss of PTEN positive expression in cancer group was associated with histological grade (P <0 · 002), depth of myometrial invasion or metastasis (P <0 · 03) and clinical stage (P <0 · 002). Conclusions The lack of PTEN expression is involved in the development and progression of endometrial adenocarcinoma. The detection of PTEN protein can be used as an early diagnosis of endometrial adenocarcinoma and to judge the biological behavior of the tumor.