Expression of estrogen receptor β in normal skin, melanocytic nevi and malignant melanomas

Sex hormones are known to be associated with increases of melanocytes and melanin production in human skin. However, the expression of estrogen receptor (ER alpha) in melanocytic lesions has been controversial. In 1996, a new subset of estrogen receptor was cloned, and named estrogen receptor beta (ER beta). We used immunohistochemical staining to characterize the expression of ER alpha and ER beta in normal skin and in melanocytic lesions. Normal sebaceous glands and hair follicles were positive for ER alpha and ER beta. Other adnexal structures and constituents in the skin were positive for ER beta, but not for ER alpha. Melanocytic nevi and malignant melanomas were negative for ER alpha, but both were positive for ER beta. The ubiquitous expression of ER beta may play a fundamental role in various normal skin cells and melanocytic tumors.