Differential expression of estrogen and progesterone receptors in endometrial polyps and adjacent endometrium in postmenopausal women.

Objective: To evaluate the immunoexpression of estrogen receptor (ER) and progesterone receptor (PR) in gland and stromal cells of endometrial polyps in postmenopausal women.

Study design: Thirty postmenopausal patients underwent operative hysteroscopies because of benign endometrial polyps. The polyps were identified and subsequently completely removed. A section of normal-appearing endometrium adjacent to the polyp base was also obtained for the control group. The presence of ER and PR was investigated in the gland and stromal cells in the polyps and adjacent endometrium using immunohistochemistry. The slides were evaluated by semiquantitative analysis.

Results: Endometrium and endometrial polyps showed a significantly higher proportion of positive cells in the glands than in the stroma for both ER (p < 0.000 and p < 0.000, respectively) and PR (p = 0.002 and p = 0.002, respectively). Polyps showed a significantly higher proportion of positive cells in glands and stroma than in the endometrium, concerning ER (p < 0.000 and p = 0.001, respectively) and also for PR (p = 0.021 and p = 0.008, respectively).

Conclusion: Our data suggest that steroid receptors present a crucial role in the physiopathology of the endometrial polyps in postmenopausal women.