Tumor-positive sentinel node biopsy of the groin in clinically node-negative melanoma patients: superficial or superficial and deep lymph node dissection?

BACKGROUND: The extent of a completion groin dissection in sentinel node-positive melanoma patients was guided by the location of the second-echelon nodes on the preoperative lymphoscintigram. The purposes of the current study were to investigate the pathological findings, the lymph node recurrences and (disease-free) survival associated with this approach.

METHODS: Between June 1996 and April 2007, 42 patients underwent completion groin dissection after a tumor-positive sentinel node biopsy. Eighteen patients had femoro-inguinal second-echelon nodes on their lymphoscintigram and underwent a superficial lymph node dissection. Twenty-four patients had iliac-obturator second-echelon nodes found by scan and underwent a combined superficial and deep dissection.

RESULTS: The median follow-up time was 61 months. One of the 18 patients who underwent a superficial groin dissection developed a deep (obturator) lymph node recurrence after 12 months. Revision of the lymphoscintigram showed that the images had been interpreted incorrectly and that the second-echelon node was located in the obturator area after all. A combined superficial and deep dissection revealed additional involved nodes in the deep lymph node compartment in 2 of the 24 patients. At 5 years, 77% of all patients were alive, and 56% were alive and free of disease. These figures were 76% and 53%, respectively, in the patients who underwent superficial dissection only, and 80% and 61%, respectively, in the patients who also underwent deep dissection.

CONCLUSIONS: This study suggests that a strategy to determine the extent of the groin dissection that is based on the location of the second-tier nodes may be valid.