ESTROGEN AND PROGESTERONE RECEPTORS IN ENDOMETRIOSIS - HETEROGENEITY OF DIFFERENT SITES

The expression of receptors for the ovarian steroid hormones oestrogen and progesterone was studied immunohistochemically using monoclonal a ntibodies in samples of endometriosis and endometrium in 22 patients. In nine patients samples of endometriosis from more than one site were studied. There was marked heterogeneity in expression of receptors in endometriosis, both when comparing lesions with the corresponding end ometrium and also between samples of endometriosis collected from diff erent sites within the same patient. It was suggested that local envir onmental factors related to the site, depth and degree of fibrosis of the lesions determine the amount of steroid hormone stimulation reachi ng the lesions and account for the observed difference between endomet riosis and endometrium and between endometriosis lesions of different sites.