[Dermatoses of the nipple and the areola]

Dermatoses of the nipple and areola are rare. The commonest dermatosis is Paget's disease, which presents in the form of a well demarcated erythematous area, sometimes erosive, oozing or hyperkeratotic. Histological examination reveals an intraepidermal proliferation of large clear cells, either isolated or grouped in clumps, predominantly in the suprabasal layers. Immunohistochemistry shows that these cells express low molecular weight cytokeratins and the epithelial membrane antigen, fairly frequently carcinoembryonic antigen. In 96% of cases, Paget's disease is associated with underlying breast carcinoma, either in situ or invasive. Erosive adenomatosis presents in the form of an erosion of the nipple, which is sometimes increased in size. Histologically, it consists of a benign tumour which may ulcerate the epidermis, composed of tubes and papillae lined by a double layer of epithelial and myoepithelial cells. The syringomatous tumour is exceptional. In places, it forms rudimentary sweat ducts and is considered to have an intermediate malignancy; its resection must be complete. Other tumours may also be observed in this site: leiomyoma, leiomyosarcoma, benign cutaneous lymphocytoma, basal cell carcinoma, naevoid areolar hyperkeratosis. They are exceptional except areolar neurofibromas in case of neurofibromatosis. Infectious dermatoses (viral warts, molluscum contagiosum, scabies) are accompanied by lesions in other sites. They same applied to the majority of inflammatory dermatoses such as eczema or Fox-Fordyce disease. Supernumerary nipples are situated on a line extending from the anterior part of the axillary crease to the medial part of the inguinal crease.