Objective: The aim of this study was to explore the potentiality of beta-catenin, Glut-1 and PTEN proteins as markers for a diagnosis of endometrial intraepithelial neoplasia (EIN).
Design: Ten proliferative endometrium, 83 endometrial hyperplasia (59 benign hyperplasia, 24 EIN) and 24 endometrioid adenocarcinoma sections were immunostained for beta-catenin, Glut-1 and PTEN protein expression.
Results: (1) Abnormal expression of beta-catenin was detected in 10% of benign hyperplasia, 50% of EIN and 67% of endometriold adenocarcinoma. (2) Overexpression of Glut-1 was present in 58% of EIN and 71% of endometrioid adenocarcinoma. (3) Complete loss of PTEN immunoreactivity was found in 20% of proliferative endometrium, 29% of benign hyperplasia, 38% of EIN and 63% of endometrioid adenocarcinoma.
Conclusions: The abnormal expression of beta-catenin and overexpression of Glut-1 may be useful markers in distinguishing benign hyperplasia from EIN, whereas lack of PTEN expression is not an appropriate marker for a diagnosis of EIN.