Clinical and dermoscopic criteria related to melanoma sentinel lymph node positivity

Background: The early detection of lymph node metastases may have important prognostic and therapeutic implications in melanoma patients. The purpose of this study was to investigate whether specific clinical and/or dermoscopic features could be "in vivo" predictors of sentinel lymph node (SLN) positivity in melanomas >1 mm thick. Materials and Methods: Five Italian centres (Istituto Dermopatico dell'Immacolata, IDI, Rome; Skin Cancer Unit, Oncologia Dermatologica, CPO, Ravenna; Istituto Europeo Oncologico, Milan; Centro di Riferimento Oncologico, Aviano; Istituto Nazionale Tumori, Naples) carried out a blind retrospective study on 508 melanomas observed from January 1994 to December 2002. The clinical and dermoscopic features of 78 melanomas >1 mm thick with the SLN biopsied were reviewed. Results: The tumour palpability was the only factor correlated to SLN positivity in melanomas >1 mm thick. Palpability was found in 46.2% of nodal positive melanomas and in 18.5% of nodal negative melanomas (p = 0.03). The patients with palpable melanomas showed a higher risk of nodal metastasis (OR=3.8). Dermoscopy failed to recognize predictive criteria for SLN positivity. Some clinical and dermoscopic features, although not statistically significant, showed interesting differences between nodal-negative and nodal-positive melanomas. Conclusion: Melanoma palpability may suggest the presence of nodal metastasis in >1 mm thick tumours.