Abstract

Cryostat sections of unfixed human endometrial tissue from normal, hyperplastic, and carcinomatous endometrium were assayed for oestrogen receptor content using a radiolabelled oestradiol binding assay with isoelectric focusing to separate receptor proteins. The proportions of myometrium, stroma, and glandular tissue were estimated in adjacent sections by point counting. Further cryostat sections were stained for oestrogen receptor immunohistochemically with a monoclonal antibody and the relative staining intensity of the various tissue components assessed. The area proportions and relative immunohistochemical staining intensity of each tissue component in the cryostat sections were then used to adjust the biochemical results and derive separate values of oestrogen receptor content in myometrium, glands, and stroma. The greatest difference in oestrogen receptor content through the menstrual cycle and between normal, hyperplastic, and malignant endometrium occurred in the glandular element.