Sentinel lymph node biopsy (SLNB)

Lymphatic mapping and SLNB should be considered to assess the presence of occult metastasis in the regional lymph nodes of patients with primary tumors measuring at least 0.8 mm thick with clinically negative nodes. These procedures may identify individuals who can avoid regional lymph node dissection and individuals who may benefit from adjuvant therapy.[5-10]

Multiple studies have demonstrated the diagnostic accuracy of SLNB, with false-negative rates of 0% to 2%.[5,10-15] To ensure accurate identification of the sentinel lymph node, lymphatic mapping and removal of the sentinel lymph node are ideally performed during the same operation as the wide excision of the primary melanoma.

If micrometastatic melanoma is detected, active surveillance with ultrasound of the draining nodal basin is an acceptable treatment recommendation that has widely replaced complete lymph node dissection (CLND). A complete regional lymphadenectomy can be considered in select populations.

For clinically node-negative patients, there is insufficient evidence to define the role of SLNB in sinonasal, anorectal, or vaginal melanoma. However, SLNB has shown feasibility and accuracy in vulvar melanoma.[16,17] Therapeutic dissection is indicated for clinically positive regional nodes in the absence of distant disease.