Immunohistochemical analysis of estrogen and progesterone receptors in endometrium and peritoneal endometriosis: a new quantitative method

OBJECTIVE: To evaluate estrogen receptors (ER) and progesterone receptors (PR) content in glandular and stromal cells of eutopic and ectopic endometrium. DESIGN: A recently advanced stereographic computer technology was applied for the investigation of steroid receptors. SETTING: University hospital department of gynecology. PATIENTS: Biopsies of endometrium and typical peritoneal endometriotic lesions were taken from 19 infertile patients with laparoscopically proved endometriosis. Endometrial biopsies were also taken from 15 patients without endometriosis. All of them were untreated. RESULTS: In normal endometrium, the highest concentrations of ER and PR occurred in the epithelial and stromal cells during the late proliferative phase of the menstrual cycle. Estrogen receptor and PR content declined throughout the secretory phase. Progesterone receptor content was found not to be significantly decreased in the stroma during the early secretory phase and quite high in the late secretory phase. In peritoneal endometriotic lesions, the highest concentrations of ER and PR were found during the late proliferative phase. When compared with normal endometrium, a lower ER content ans a similar PR content were observed, and the cyclic changes in peritoneal endometriosis lesions were also similar. CONCLUSION: A new computerized technology for the evaluation of ER and PR in eutopic and ectopic endometrium. Although the ER content was found to be lower in endometriotic tissue when compared with endometrium, the cyclic pattern was similar in both eutopic and ectopic endometrium. Progesterone receptor content was similar in both tissues, except during the late secretory phase in ectopic glandular epithelium in which a high persistent PR content was observed.