Primary Melanoma Histopathologic Predictors of Sentinel Lymph Node Positivity: A Proposed Scoring System for Risk Assessment and Patient Selection in a Clinical Setting.

Univariate regression analysis showed the Breslow thickness ( p = 0.008), the mitotic index rate ( p = 0.054), the presence of ulceration ( p = 0.009), as well as the T3-4 stage ( p = 0.009) to be significant predictors of SLN positivity.

The optimal cut-off values for Breslow thickness and the number of mitoses scores were determined based on ROC curve analysis.

Using the Breslow thickness, mitotic index rate, presence of ulceration, and T3-4 stage significant coefficients from the univariate regression model, a chance prediction score was developed.