Altered PTEN expression; a diagnostic marker for differentiating normal, hyperplastic and neoplastic endometrium

In a study in a referral gynecologic hospital in Tehran, Iran, immunohistochemical (IHC) evaluation of PTEN was performed on 87 consecutive specimens to the following three groups; group A- normal proliferative endometrium(n = 29); group B- hyperplastic endometrium [including simple hyperplasia without atypia(n = 21) and complex hyperplasia with atypia (n = 8)] and group C- EECA(n = 29). Immunostaining of cells was analyzed by arbitrary quantitative methods according to both slide's area staining and intensity of color reaction.PTEN immunoreactivity was present in all normal proliferative endometrium, all simple hyperplasia, 75% of atypical complex hyperplasia and in 48% of EECA (P < 0.001). The intensity of PTEN reaction was significantly higher in group with proliferative endometrium than hyperplastic endometrium and EECA (P < 0.001).PTEN expression was significantly higher in cyclical endometrium than in atypical hyperplasia and endometrioid carcinoma.Endometrioid endometrial carcinoma (EECA) accounts for three fourths of endometrial cancers and are thought to develop following a continuum of premalignant lesions ranging from endometrial hyperplasia without atypia, to hyperplasia with atypia and finally to well differentiated carcinoma[1,2]. Based on light microscopic appearance and clinical behavior, endometrial cancers have long been classified into major categories (type I and II) [2-4]. Accurate diagnosis of premalignant lesions in routine endometrial biopsies has a great clinical value in patient management. Unfortunately several recent studies have shown that cytological atypia which is predominant criterion for diagnosis of premalignant lesions (atypical endometrial hyperplasia), have poor reproducibility [1,3]. Therefore, solving these problems needs new insights into the morphology of biologically defined premalignant lesion of endometrium [1]. Recent molecular diagnostic methods have provided new ancillary tools for premalignant lesion diagnosis. EECA h