Melanoma is one of the most aggressive solid cancers, although mortality can be reduced with early treatment. Immunotherapy has transformed the prognosis of this pathology.

The sentinel lymph node technique is used to classify the severity of melanoma. It is proposed for melanomas with a Breslow thickness of 0.8 mm to 1 mm, and recommended for melanomas greater than 1 mm or with ulceration, whatever the Breslow index.

This technique is particularly useful for assessing pathology by detecting the presence of lymph node metastases. Patients with lymph node involvement (micro or macro) are eligible for adjuvant treatment.

The new recommendations suggest adjuvant immunotherapy for stages IIB and IIC (without lymph node involvement assessed by the sentinel lymph node technique). This procedure is widely used at the CHRU de NANCY.

The aim of this study is to demonstrate the value of the sentinel lymph node in assessing the risk of melanoma recurrence at one year (or more).

Inclusion Criteria:

Major patient with a melanoma with a Breslow index greater than 0.8mm or ulcerated melanoma, non-metastatic at diagnosis,

Exclusion Criteria:

• Metastatic patient
• Minor patient
• Melanoma with a Breslow index of less than 0.8mm and not ulcerated
• Patient objecting to data collection

Patients followed at the CHRU de Nancy or at the ICL between 01/01/2019 and 31/12/2023 and who does not object to the collection of his/her data.