Melan-Cohort should constitute the first multicentric cohort with various objectives: prognostic, therapeutic, cognitive and medico-economical studies on melanoma. Patients will be recruited in all of the dermatology departments of APHP (dermatology departments from AMBROISE PARE, Saint-Louis, BICHAT-Claude Bernard,Henri-Mondor, Cochin-Tarnier, and Tenon hospitals). For all included patients, a standard file is filled comprising all anatomy-clinical useful data and epidemiologic ones, including sun exposures. Blood is harvested to collect DNA, RNA, serum, plasma at inclusion and at regular intervals and in case of progressive disease. Procedures for sentinel lymph node biopsies have been homogenized. An informed consent is obtained for each patient included in the cohort. A steering committee meets on a regular basis, and genetics or pathology subgroups have been constituted. An electronic CRF is available using the Intranet of APHP hospitals. Specimens are stored using high quality standards.