The surgical management of the sentinel lymph node in cutaneous melanoma might be different when the primary lesion was previously resected with 1 cm margin.

Aim: To simulate the effects of previous wide cutaneous melanoma excision in sentinel lymph node (SLN) biopsy feasibility through a change in the radiotracer injection site.
Materials and Methods: Thirty-three patients with cutaneous melanoma underwent two preoperatory lymphoscintigraphic studies. In the first, the radiopharmaceutical was injected intradermally 0.3 cm away from the lesion/scar. Dynamic images were acquired to find the SLN. On the following day, the procedure was repeated with the radiopharmaceutical injected 1 cm farther from the previous injection sites. The number of lymph nodes and sites of drainage were compared with the findings of the first study. All the patients underwent SLN biopsy using a gamma probe and patent blue.
Results: Seventy-five SLNs were identified with radiopharmaceutical injected at 0.3 cm from the lesion versus 82 SLNs when injected at 1.3 cm. All lymph nodes visualized with close injection were identified with the farther injection. Twenty-seven (81%) patients presented the same number and location of SLNs. Six (19%) patients presented more SLNs with the expanded technique, three patients in the same basin and three in a new lymph node station. All metastatic SLNs were harvested by the two injection techniques.
Conclusion: The value of the SLN biopsy in patients with cutaneous melanoma is maintained even after the primary lesion has been removed with a margin of up to 1 cm. Some patients might show an increased number of SLNs and some might show drainage to additional lymph node stations.