sentinel lymph node biopsy melanoma technique

The SLNs were then dissected and evaluated by routine hematoxylin eosin or immunohistochemistry to detect the presence of metastatic deposits. Then a blue dye was injected intradermally at the melanoma site to trace the connected lymph vessels and identify the draining sentinel node(s). Cutaneous lymphoscintigraphy with technetium-labeled dextran was used to identify the areas of primary drainage for melanomas located in ambiguous sites. In 1992, Morton et al., published an operative procedure using this technique to select and remove SLNs and identify patients with metastatic nodes. This simple observation developed into the revolutionary concept of the SLNB. He realized that knowing the status of this “sentinel” node made it possible to know the status of the entire regional basin. The first node draining directly from the site of the primary lesion was the first at risk of being reached by cancer cells spreading from the tumor. Dr Morton explained that it was during a lymphoscintigraphy-while observing the dynamic images of a lymphatic channel draining directly to a first node, and then into the secondary nodes-that the idea of the “sentinel” node was born. Morton developed a technique called cutaneous lymphoscintigraphy to map lymphatic drainage pathways in truncal or shoulder melanomas. Another issue with ELND was to identify the basins at risk of metastasis when cutaneous melanoma developed in sites with ambiguous lymphatic drainage pathways.

The primary shortcoming of ELND is that only about 20% of patients with an intermediate-thickness primary melanoma are expected to have metastases in the regional nodes, whereas 80% of patients are exposed to the morbidity of lymphadenectomy, without actual benefit.

indicated that ELND improved survival in certain subgroups, such as in patients aged 60 or younger, or with 1 to 2-mm thick or non-ulcerated tumors. Several prospective randomized controlled studies have shown that ELND has no benefit in patients with cutaneous melanoma, but subgroup analysis in the trial conducted by Balch et al. However, the efficacy of this procedure has been long debated. Snow in 1892 to halt tumor progression, regardless of the absence of palpable nodes. Prophylactic removal of regional nodes by routine ELND was recommended for the first time by Herbert L. History of the Sentinel Lymph Node Biopsy

Sentinel lymph node biopsy melanoma technique