Melanoma tumor tissue ( in particular regressive areas) present a lymphocytic infiltrate with an anti-tumoral specificity. The aim of the study is to analyse at different stages of the disease, tumor samples and to characterise the cellular infiltrate in situ ( in particular T lymphocytes, NK cells and macrophages), the role of inhibitor receptors on in situ immunosuppression, and potential modulation by medical treatments such as dacarbazine.

The study is divided in 4 parts:

Part 1: study of cellular infiltrate (lymphocytes) performed on large primary melanoma and cutaneous metastasis ( fresh samples) Part 2: NK cells study on metastatic regional lymph nodes ( fresh samples) and blood samples Part 3: a retrospective study of macrophages in sentinel lymph nodes and in corresponding primary melanomas Part 4: study of the cellular modulation by the chemotherapy (DTIC or cisplatin or inhibitor of B-raf) which(who) will be made on two cutaneous metastases by patient (one taken before the treatment(processing) and one taken during the evaluation after 2 or 3 cycles of treatment(processing))

Inclusion Criteria:

• Patients with confirmed melanoma-patients informed of the aims of the study , the modalities
• Patients who signed the consent form ou a non opposition form signed by the patient or by a relative

According to study part:

Part 1: patients with a melanoma larger than 10mm or with cutaneous metastasis Part 2: stage IV melanoma patients who shall undergo a regional lymph node dissection Part 3: retrospective study of patients who underwent a sentinel node procedure Part 4: Patients achieves of inoperable melanomas the stage(stadium) III or IV that must receive in treatment (processing) a chemotherapy (by the dacarbazine or by the cisplatin or by the inhibitor of B-raf) and carrier of at least two cutaneous metastases

Exclusion Criteria:

• Refusal to take part in the study (patient or relative)
• Contraindications known to the xylocaine (groups 1,2, and 4)
• No affiliated to the social security system (groups 1, 2, and 4)

Part 1: patients with a melanoma larger than 10mm or with cutaneous metastasis Part 2: stage III melanoma patients who shall undergo a regional lymph node dissection Part 3: retrospective study of patients who underwent a sentinel node procedure Part 4: stage IV Patient achieves of inoperable melanomas the stage(stadium) III or IV that must receive in treatment(processing) a chemotherapy (by the dacarbazine or by the cisplatin or by the inhibitor of B-raf) and carrier of at least two cutaneous metastases