IMMUNOHISTOCHEMICAL ANALYSIS OF PROLIFERATIVE ACTIVITY AND STEROID-RECEPTOR EXPRESSION IN PERITONEAL AND OVARIAN ENDOMETRIOSIS

Objective: To assess the proliferative activity of eutopic and ectopic endometrium throughout the menstrual cycle and its correlation to ste roid receptor content. Design: The immunohistochemical use of Ki 67 wa s applied to investigate the proliferation index. A recently advanced stereographic computer technology was used to investigate steroid rece ptors. Setting: University hospital department of gynecology. Patient( s): Biopsies of eutopic endometrium, black and red peritoneal endometr iotic lesions, and ovarian endometriomas were taken from infertile pat ients and classified according to the phase of the cycle. Result(s): I n normal endometrium, the glandular proliferation index was highest du ring the proliferative phase and was statistically significantly reduc ed during the secretory phase. No proliferative activity was observed in the late secretory phase. No statistically significant differences were found between ectopic endometrium and eutopic endometrium except during the late secretory phase, when proliferative activity was still present in endometriotic tissue. The stromal proliferation index was similar in red lesions, ovarian endometriomas, and eutopic endometrium during the secretory phase. In normal endometrium, the highest concen trations of estrogen receptors (ERs) and P receptors (PRs) occurred in the epithelial and stromal cells during the late proliferative phase of the menstrual cycle. Estrogen receptor and PR content declined thro ughout the secretory phase. In ectopic endometrium, PR persisted in th e glandular epithelium during the late secretory phase. Estrogen recep tors persisted in the glandular epithelium and stroma of red peritonea l lesions and ovarian endometriomas during the late secretory phase. C onclusion(s): The high proliferative activity and the persistence of E Rs and PRs in the stroma of red lesions and ovarian endometriomas emph asize the primordial role of the stroma in the development of endometr iosis and suggest different mechanisms of proliferation control from t hose observed in eutopic endometrium. (C) 1997 by American Society for Reproductive Medicine.