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. In 2002, the American Joint Committee on Cancer revised the TNM staging system for cutaneous melanoma on the basis of important emerging prognostic evidence in melanoma patients (1). The new TNM classification included some fundamental changes: the Breslow thickness was considered to be the most important survival indicator in patients with localized melanoma; a new thickness threshold of 1.0 mm defined the T1/T2 stage, set at 0.75 mm in the previous (1997) version; the presence of ulceration (evidenced histopathologically) or a Clark level IV/V, upstaged the tumour to the next T level; the number of lymph nodes involved rather than their dimension was considered to be the primary determinant in N staging; the lymphatic mapping and the sentinel lymph node (SLN) biopsy were established as highly accurate techniques in pathological regional nodal staging that allow the selective application of SLN dissection only in node-positive