[Malignant melanoma]

Malignant melanoma is the most serious skin tumor and its incidence is doubling every ten years. Ultraviolet rays represent the main environmental cause of melanoma. Among the constitutional factors identified, two clinicopathological forms of naevus are considered to be important epidemiological precursors: acquired dysplastic naevi and congenital giant naevi. Four clinical and histological types are distinguished: SSM (Superficial Spreading Melanoma), NM (Nodular Melanoma), LMM (Lentigo Maligna Melanoma), arising from Dubreuilh melanosis, ALM (Acral Lentiginous Melanoma). Thickness constitutes the essential prognostic factor. Clinical examination is the only recommended standard assessment. Chest x-ray is useful, and acts as a reference for subsequent follow-up. Other complementary investigations are requested as a function of clinical signs. Treatment is exclusively surgical. The lateral resection margins are 0.5 cm for melanoma in situ, 1 cm for melanomas less than 1 mm thick, 2 cm for melanomas between 1 and 4 mm thick, and 3 cm for melanomas thicker than 4 mm. Chemotherapy is mainly used in the treatment of metastatic melanoma. There is no indication for radiotherapy apart from palliative treatment of nonsurgical metastases. New therapies such as immunotherapy and gene therapy are under investigation.