The MATRIX criteria: an internally validated scoring model for biopsy selection in longitudinal melanonychia

An internally validated weighted MATRIX predictive model was developed to improve biopsy decision-making in patients with longitudinal melanonychia. In a tertiary-center cohort, MATRIX demonstrated superior diagnostic performance compared with the ABCDEF criteria and the dermoscopy-specific model. These findings support MATRIX as a practical clinical tool for early detection of subungual melanoma.