Immunohistochemical localization of estrogen receptors in the vulva and vagina.

A rat monoclonal antibody against human estrogen receptor (ER) was used to localize nuclear ER in frozen tissue sections with the peroxidase-antiperoxidase technique. Premenopausal and postmenopausal vaginal, vulvar and nongenital skin was examined. ER was demonstrated in some but not all of the nuclei of basal and suprabasal differentiated epithelial cells of the vagina. ER was seen in the fibroblasts and smooth muscle, but not in the vessel endothelium, of the underlying stroma. ER was demonstrated in epidermal keratinocytes and dermal fibroblasts of the vulva and perineum, hair and non-hair bearing, but at a much lower frequency than in the vagina. Specific ER staining was not detected in the majority of skin specimens for extragenital sites. These findings have implications for the hormonal regulation of the vulva and for the use of estrogen cream in managing vulvar conditions.