Failure to identify sentinel lymph nodes for malignant melanoma – Outcome after over 10 years median follow up

Background: Sentinel lymph node biopsy (SLNB) is routinely performed during surgery for malignant melanoma, using double mapping. Still, in some cases, a sentinel lymph node identified pre-operatively by lymphoscintigraphy is not identified during surgery. We hypothesized that disease specific survival would not be significantly impacted by intra-operative lymph node mapping (IOLM) failure. Methods: The patient population study included 1300 malignant melanomas operated on by a single surgical oncologist (H.G.) after sentinel lymph node scintigraphy. Patients were included in the analysis if intra-operative lymph node (IOLM) mapping failed. Results: Among 1300 patients who underwent surgery for malignant melanoma during the study period and after median follow up of >10 years, 33/36 lymphatic drainage basins with failed sentinel node identification were free of disease. Disease specific survival for the entire group of 33 patients with IOLM failure was 91.0%, which is comparable to previously published disease specific survival for all melanoma patients. Conclusion: We conclude that failure to identify a pre-operatively marked sentinel lymph node by an experienced melanoma surgeon has, generally, no impact on disease specific survival, as demonstrated in this review of a series of surgical melanoma patients.