[Extra-mammary Paget's disease of the scrotum].

An 82-year-old man presented with an itching rash on his scrotum that he had had for several years. Histopathological examination revealed a normal epidermis with multiple atypical cells, organised both solitary and group-wise within the epidermis. The diagnosis of extra-mammary Paget's disease (EMPD) was made. Further investigation showed no signs of underlying malignancy. The man was operated upon and the lesion was completely removed. EMPD is an intra-epidermal adenocarcinoma, found in areas with apocrine sweat glands. Primary EMPD (75%) probably arises from pluripotent stem cells in the epidermis. Over time it can invade the dermis and deeper tissues and metastasize. In secondary EMPD (25%) there is epidermal invasion of malignant cells of skin adnexal adenocarcinomas, or there is an association with adenocarcinomas of nearby internal organs. Immunohistochemical investigation may help to discriminate between primary and secondary EMPD. Average mortality is 26%. Treatment depends on the presence of an underlying malignancy, but surgery is the preferred option. The risk of relapse varies from 8 to 61%, which makes a long-term follow-up necessary.