[Dysplastic nevus syndrome].

Dysplastic nevus syndrome is an autosomally dominant disease, which may develop hereditary malignant melanoma. Dysplastic nevi are found anywhere on the body surface and show definite clinical characteristics. Histologic examination reveals atypical melanocytes at the dermo-epidermal junction and inflammatory infiltration in the dermis. The dysplastic cells show either lentiginous or epithelioid dysplasia. The evolution towards malignant melanoma always starts with the development of epithelioid melanocytes in the epidermis. Sunlight might further the mechanism of degeneration. Thus dysplastic nevus syndrome becomes important for the possible recognition and prevention of potential malignant melanoma.