Evaluation of melanoma features and their relationship with nodal disease: the importance of the pathological report.

Background: The pathological features of melanoma biopsies can provide significant prognostic information that can help the surgeon evaluate the risk of nodal disease. The aim of this study was to attempt to determine the relationship between pathological features of primary melanoma and nodal disease, by sentinel node biopsy (SNB) and complete node dissection (CND).

Methods: A retrospective analysis was completed of patients who underwent SNB at AC Camargo Cancer Center, São Paulo, Brazil, between 2000 and 2010.

Results: A total of 697 patients were evaluated. By univariate analysis, it was found that histology, Clark level, Breslow depth, mitotic index, ulceration, regression, lymphatic and perineural invasion and satellitosis were significantly associated with SNB positivity. In the multivariate analysis, it was found that Breslow depth, mitotic index, ulceration, regression, lymphatic invasion and satellitosis were significant factors. In patients with a positive SNB, the primary tumor site, Clark level and Breslow depth greater than 2 mm were significantly related to non-sentinel node (NSN) positivity by univariate analysis. By multivariate analysis, Breslow depth greater than 2 mm was the only primary tumor feature that was significantly related (p = 0.038).

Conclusions: The indication of SNB should not be based solely on Breslow depth and ulceration or mitotic index. A complete evaluation of the pathological report should improve the identification of high-risk patients.