Histopathological predictive factors of sentinel node positivity in melanoma in the Blumenau-SC Brazilian region

This study aims to evaluate the relationship between sentinel lymph node positivity and risk factors associated with cutaneous melanoma, as well as the epidemiological data of patients diagnosed with this condition in the Blumenau-SC region.

This is a cross-sectional study analyzing medical records of patients diagnosed with melanoma who underwent sentinel lymph node biopsy at a nuclear medicine service in Blumenau, Santa Catarina. The variables analyzed included Breslow classification, Clark classification, regression, ulceration, histological subtype, age, and sex. Patients were divided into two groups: those with a positive diagnosis and those with a negative diagnosis.

The variables with the highest statistical significance were: histological subtype, with nodular melanomas associated with positivity (P < 0.001); ulceration, which was more prevalent in the positive group (P = 0.0018); Breslow classification, which showed a significantly higher mean in the positive group (P = 0.0002, Mann-Whitney test); and Clark level, which was significant in patients with higher classifications. Other variables analyzed did not show statistical significance.

The mitotic index was not analyzed as a variable; this study was based on the 7th edition of the American Joint Committee on Cancer (AJCC) cancer staging manual.

This study presented results consistent with current literature, confirming the predictive values of sentinel lymph node positivity, aiding in better patient selection for this invasive procedure, and avoiding unnecessary analyses that may lead to irreversible adverse effects.