Analysis of estrogen- and progesterone-receptor expression in endometrial polyps

Study objectiveTo investigate the presence of estrogen receptors (ER) and progesterone receptors (PR) in the glandular epithelium and stroma of endometrial polyps in women who underwent hysteroscopic polypectomy.DesignProspective study (Canadian Task Force classification II-3.SettingHospital de Servidor Público Estadual de São Paulo “Francisco Morato de Oliveira.”PatientsForty-eight patients with a solitary endometrial polyp who underwent hysteroscopic polypectomy and resection of an endometrial fragment.InterventionThe estrogen and progesterone receptor expression, in the polyp, was compared with the endometrial hormone expression of the same patients.Measurements and main resultsThe specimens were analyzed by immunohistochemistry. The percentage of staining cells was determined as follows: grade I, 0% to 25%; grade II, 26% to 50%; grade III, 51% to 75%; and grade IV, 76% to 100% of stained nuclei. The intensity of nuclear staining was classified as grade I, absent; grade II, weak; grade III, strong; and grade IV, very strong staining. The sum of both grades was the histochemical score. The total scores of polyp and endometrium were statistically compared. The total scores of ER of glandular epithelium were 258 in polyp and 211 in endometrium. As to stroma, it was 155 in polyp and 163 in endometrium. The total scores of PR of glandular epithelium were 286 in polyp and 211 in endometrium. As to stroma, the totals were 76 in polyp and 77 in endometrium. In immunohistochemistry, the concentrations of both ER and PR in glandular epithelium were significantly higher in endometrial polyp than in normal endometrium. The concentrations of ER and PR in the stroma were similar in the polyp and endometrium. The concentrations of these receptors in the glandular epithelium and stroma were similar in postmenopausal and premenopausal patients.ConclusionThe concentrations of ER and PR in glandular epithelium were significantly higher in endometrial polyp than in normal endometrium. The concentrations of these receptors in the glandular epithelium and stroma were similar in the postmenopausal and pre-menopausal patients.