[Melanoma cutáneo. Etapificación ganglionar con base en la evidencia actual]

Most patients with cutaneous melanoma present with clinical stage 1 at diagnosis, i.e., with no evidence of lymph node or systemic metastases. However, since this is a type of neoplasm with high affinity to lymphatic tissue, between 30 and 60% of patients are estimated to have occult metastases on the lymph nodes of the area that drains the primary tumor site at the moment of diagnosis. This possibility depends on several histologic factors, especially thickness of the neoplasm. Historically, in order to reduce the rate of regional recurrence, lymphadenectomy was an essential part of cutaneous melanoma treatment, which has associated morbidity. In the decade of 1990, Morton et al. reported that lymph is initially received by a single lymph node in the lymphatic basin and that its histological status predicts the status of the others and that, therefore, in patients with sentinel lymph node free of metastases lymphadenectomy is not necessary, which reduces morbidity. In the present manuscript, indications, contraindications and requirements for sentinel lymph node identification are described, as well as its current value in cutaneous melanoma diagnostic and therapeutic process.