Immunohistochemical expression of the tumour marker CA-125 in normal, hyperplastic and malignant endometrial tissue.

Introduction: The aim of this study was to determine the tissue distribution of CA-125 in normal, hyperplastic and malignant endometrium. Materials and Methods: Endometrial tissue was obtained from women in proliferative (n=5), early secretory (ES; n=4) and late secretory (LS; n=4) phase as well as glandular-cystic hyperplasia (n=5), endometrial polyps (n=5), endometrial polyps caused by tamoxifen use (n=5), adenomatous hyperplasia (AH) grade I (n=5), grade II (n=4), grade III (n=5) and endometroid adenocarcinoma (n=5). The CA-125 expression was evaluated with the semiquantitative IRS-Score. Results: CA-125 expression was observed in glandular and luminal epithelial cells, being significantly higher during LS than ES. The highest CA-125 reaction was observed in AH 111 in glandular and luminal cells, which was statistically higher compared to all groups (except glandular cells: proliferative and LS; luminal cells: AH I-II, glandular-cystic polyps). Discussion: CA-125 was expressed in normal, hyperplastic and malignant endometrial tissue with a cyclical expression in premenopausal endometrial glandular cells. Adenocarcinoma expressed CA-125 with a lower intensity. The highest expression was observed in AH III in luminal and glandular cells, therefore CA-125 could be a marker of malignant cell transformation.