Implications of Sentinel Lymph Node Drainage to Multiple Basins in Head and Neck Melanoma.

BACKGROUND: Sentinel lymph node biopsy (SLNB) for head and neck melanoma is challenging due to unpredictable drainage. We sought to determine the frequency of drainage to multiple lymphatic basins and asked if this was associated with prognosis in a large, single-center cohort.

METHODS: We queried patients diagnosed with head and neck melanomas who had a SLNB performed from January 1998 to April 2016. Demographic and clinical characteristics were compared using Student's t test, Pearson chi-square analysis, log-rank test, Wilcoxon-Mann-Whitney test, and Kaplan-Meier curves.

RESULTS: We identified 269 patients with head and neck melanoma that had SLNBs performed in the following locations: 223 neck, 92 parotid/preauricular, 29 occipital/posterior auricular, 1 axilla. There were 68 (25%) patients who had drainage to multiple basins. These patients were similar to those with single basin drainage in age, gender distribution, Breslow depth, and percent with a positive SLNB (all p > 0.05). Fewer patients with drainage to multiple basins had a completion lymph node dissection (CLND, p = 0.03). A trend toward increased 3-year locoregional recurrence was seen for patients with drainage to multiple basins in univariate analysis (27% vs. 18%, p = 0.10) but was lost in multivariate analysis (p = 0.49), possibly because of higher recurrence rates in patients with positive nodes but no CLND (p = 0.02). No difference was detected for distant recurrence or overall survival based on SLN drainage.

CONCLUSIONS: Head and neck melanoma SLNB drainage to multiple basins is common. Drainage to multiple basins does not seem to be associated with increased sentinel lymph node positivity, locoregional recurrence, distant recurrence, or survival.