INTRODUCTION: Sentinel lymph node (SLN) biopsy is an important independent 
prognostic factor for invasive cutaneuos melanoma, although its role is strongly 
debated. In clinical practice SLN leads to complete lymph node dissection of 
basin draining melanoma site. However only 7-30% of positive sentinel node 
patients present additional non SLN metastasis. Melanoma cells diffusion through 
SLN and extranodal spreading depends upon biological features, such as cell 
chemokine receptors and adhesion molecules. CXCR4 has been proposed in melanoma 
patients as prognostic marker. Therefore we have analyzed both histopathological 
parameters and CXCR4 expression in melanoma infiltrate of SLN, in order to 
evaluate its potential prognostic role.
RESULTS: Micrometastases were detected in 23 cases (48.93%); metastases >2 mm in 
23 cases (48.93%) and isolated metastatic cells in one case (2.01%). High CXCR4 
expression was observed in 21 nodal metastases. Node metastases in complete 
dissection were associated to >10% relative tumor area (RTA) in all lymph nodes 
(p = 0.006). Extranodal invasion (p = 0.006) and >2 mm centripetal metastasis 
thickness (p = 0.01), while shorter Disease Free Survival (DFS) was 
significantly associated to high CXCR4 expression (p = 0.02).
MATERIALS AND METHODS: Forty-seven positive lymph node metastases were collected 
and analysed for both histopathological parameters and CXCR4 expression.
CONCLUSION: More than 10% RTA in SLN, extranodal invasion and centripetal 
metastasis thickness all predict additional lymph node metastases in melanoma 
site draining basins. Moreover, high CXCR4 expression is correlated to shorter 
DFS and could be used as a prognostic marker in order to stratify melanoma 
patients at higher progression risk.