Prognostic significance of histopathological parameters in sentinel nodes of melanoma patients.

AIMS: The presence of micrometastases in the sentinel lymph node (SLN) is an important prognostic parameter for melanoma patients. The aim was to determine the prognostic relevance of histopathological characteristics of micrometastases in the SLN, which has not been adequately addressed thus far.

METHODS AND RESULTS: In 169 melanoma patients with positive SLN, histopathological features of the SLN were correlated with overall survival (OS) and relapse-free survival (RFS). Tumour burden, expansion of melanoma cells in the periphery (infiltration of capsule) and towards the centre of the SLN [tumour penetrative depth (TPN)] were of prognostic significance for OS and RFS on univariate analysis. Multivariate analysis revealed three independent significant parameters which predict a poor prognosis: presence of infiltration of the SLN capsule, TPN > or = 2 mm and size of the largest tumour deposit > or = 30 cells.

CONCLUSIONS: Histopathological analysis of SLN allows the identification of patients with a poor prognosis depending on the location of melanoma cells and tumour burden.