In many patients with cutaneous melanoma affecting the trunk area, there is lymphatic drainage to multiple basins (MLBD). This study aimed to examine whether MLBD is associated with disease outcome.

Lymphatic mapping and sentinel lymph node (SLN) biopsy were performed in 161 patients with truncal melanoma. The number and location of draining nodal basins were established during the preoperative lymphoscintigraphy using technetium-99m rhenium sulphide nanocolloid.

MLBD was present in 59 (37%) patients, and a single lymphatic basin drainage (SLBD) in 102 (63%) patients. Patients with MLBD showed no increased risk for SLN metastasis compared to patients with a SLBD (27% versus 29%, respectively). There was no significant difference in disease-free survival (DFS) between patients with MLBD and patients with a SLBD. Five-year DFS was 64% for patients with MLBD and 64% for patients with a SLBD. Multivariate analysis showed that the presence of ulceration (p = 0.01) was an independent predictor of SLN metastasis, while melanoma thickness (p = 0.01) and SLN metastasis (p = 0.01) were independent predictors of DFS. In patients with a negative SLN, five-year DFS was 74% for patients with MLBD and 73% for patients with a SLBD. Multivariate analysis showed that melanoma thickness (p = 0.00) was an independent predictor of DFS.

MLBD does not have a negative impact on the disease outcome in patients with truncal melanoma.