Diseases of the male nipple and areola.

The male nipple-areola-complex (NAC) is a residual organ without physiologic functions in the male. It possesses similar hormone sensitivity and sexual sensitivity as the female organ. The location of the NAC on the chest wall with respect to other surface features is relevant for the male appearance. All known disseminated skin diseases may involve the nipple and areola. A number of specific localized diseases have been described in the literature, such as mammillary eczema, demodicidosis, lymphadenosis cutis benigna, nevoid hyperkeratosis, and thelalgia. Special attention is required if nipple discharge is observed. Areolar sebaceous hyperplasia and nearly all kinds of benign cutaneous tumors occur on the nipple and areola. Malignant tumors such as basal cell carcinoma, melanoma, Paget disease and other forms of breast cancer may also be found. In addition, aberrant mammary tissue may occur with a broad clinical spectrum, while absence of the nipple is an unusual observation and occurs in rare syndromes. The association of aberrant mammary tissue with urinary tract malformations has not been confirmed.