Nonvisualization of Sentinel Lymph Nodes by Lymphoscintigraphy in Primary Cutaneous Melanoma – Incidence, Risk Factors, and a Review of Management Options

PURPOSE: Lymphoscintigraphy (LS) is often obtained prior to sentinel lymph node biopsy (SLNB), especially in areas likely to have multiple or aberrant drainage patterns. This study aims to determine the incidence and characteristics of melanoma patients with a negative LS and to review the management options and surgical recommendations. METHODS: This is a retrospective study of patients with primary cutaneous melanoma who underwent SLNB between 2005 and 2016. Patients with nonvisualized lymph nodes on preoperative LS were compared in a 1:4 ratio with a randomly selected unmatched cohort drawn from all melanoma patients who underwent preoperative LS within the time period of the study. Demographic, clinical and outcome data were compared between these groups. RESULTS: A negative LS was seen in 2.3% of all cases (25 in 1073). In both univariate and multivariate analyses, predictive patient and tumor-specific factors for negative LS included older age and head and neck location. Patients with a non-visualized SLN had significantly worse overall survival compared with patients who had a visualized SLN, but there was no difference in melanoma-specific survival. In 16 of the 25 cases (64%), at least one SLN was found intraoperatively despite the negative LS. CONCLUSION: Older patients with head and neck melanomas are more likely to experience nodal nonvisualization on LS. In patients who have nodal nonvisualization, the surgeon should attempt SLNB at the time of excision of the primary lesion since a SLN can still be found in a majority of cases, and it offers prognostic information. CONFLICTS OF INTEREST AND SOURCE OF FUNDING: None of the authors have a financial interest in or a commercial association with any of the products, devices, or drugs mentioned in this manuscript. There was no source of funding for this manuscript. CORRESPONDING AUTHOR: Dr. Deepak Narayan, Yale University School of Medicine, Section of Plastic Surgery, 330 Cedar Street, P.O. Box 208041, New Haven, CT, 06520-8041, United States. Phone number: (203) 785-2570, Fax number: (203) 785-5714, deepak.narayan@yale.edu ©2018American Society of Plastic Surgeons