Immunohistochemical Study of Calretinin in Normal Skin and Cutaneous Adnexal Proliferations

The study investigated the expression of calretinin, a calcium-binding protein, in normal skin and cutaneous adnexal proliferations using 139 biopsy specimens. In normal skin, calretinin was found in the innermost cell layer of the outer root sheath in anagen hair follicles, sebaceous glands, eccrine glands, and mast cells. In cutaneous adnexal proliferations, strong immunoreactivity for calretinin was observed in various tumors, including tricholemmal cysts and basal cell carcinomas, among others. The findings suggested that calretinin could be a useful marker for identifying certain skin structures and differentiations, particularly in hair follicles and sweat gland neoplasms.