PROLIFERATIVE ACTIVITY OF POSTMENOPAUSAL ENDOMETRIOSIS - A HISTOPATHOLOGIC AND IMMUNOCYTOCHEMICAL STUDY

Histological features of 21 cases of postmenopausal endometriosis as w ell as the corresponding eutopic endometrium were studied. Immunocytoc hemical analysis of estrogen receptor (ER), progesterone receptor (PR) , and Ki-67 nuclear antigen was also performed on the endometriotic le sions as well as the corresponding endometrium. All the cases studied were complicated by various other gynecologic diseases, making the pre operative diagnosis of endometriosis unlikely. Histologically, the end ometriotic foci contained both epithelial and stromal components mostl y lacking atrophic features in contrast to the corresponding eutopic e ndometrium. The endometriotic lesions and the corresponding endometriu m exhibited immunoreactivity with ER in both the glands and stroma. Th e stromal cells of endometriotic lesions revealed positive PR staining , whereas those of the eutopic endometrium were either negative or wea kly positive for PR, but the epithelial components of both were positi ve for PR. The positivity of Ki-67 antigen tended to be higher in the stroma of the postmenopausal endometriosis than in the eutopic endomet rial stroma. Endometriotic lesions appear to remain biologically activ e, with proliferative activity as well as retained hormonal responsive ness, even in the low-estrogen milieu of the postmenopausal age.