Hormone receptor expressions and proliferation markers in postmenopausal endometrial polyps

Endometrial polyps are quite common in the general population, they have a significant role in postmenopausal bleeding, and the pathogenesis is unclear. The aim of this study was to investigate proliferation markers and expression of estrogen and progesterone receptors in endometrial polyps in postmenopausal women.

Endometrial polyps were removed by hysteroscopy from 36 women who presented with postmenopausal bleeding. None were using hormonal therapy. The control group consisted of 16 inactive-atrophic postmenopausal endometrial specimens removed at hysterectomy. Immunohistochemistry was used to demonstrate expression of estrogen and progesterone receptors and the cell growth and apoptosis markers, Ki67, bcl-2, c-erbB-2.

In both the glandular epithelium and stroma of endometrial polyps, estrogen and progesterone receptors, Ki67 and bcl-2 showed significantly more positive staining than the inactive endometrium from the control group. There was no difference in expression of c-erbB-2 between the two groups.

Estrogen may have a role in the development of postmenopausal endometrial polyps, either by direct stimulation of localized proliferation or by stimulation of proliferation via other pathways, such as activation of Ki67 or through inhibition of apoptosis via bcl-2. c- erbB-2 is unlikely to play any role in development of these lesions.