MPATH-Dx version 2.0 schema for melanocytic lesions: A robust tool for standardized diagnostic reporting.

The new revised MPATH-Dx (version 2.0) reporting schema for melanocytic lesions is presented. Principal changes include the simplification of the previous five-class version 1.0 to a four-class hierarchy of melanocytic lesions to improve diagnostic agreement and to provide more explicit guidance for the management of patients. Version 2.0 also has clearly defined histopathologic criteria for classification of class I and II lesions, which are now designated as low-grade (mild-to-moderate) atypia and high-grade (high-end moderate-to-severe) atypia, respectively. This new revised schema also includes specific provisions for the less common World Health Organization pathways to melanoma, provides guidance for classifying "intermediate" class II tumors (melanocytomas), and recognizes a subset of pT1a melanomas with very low risk and possible eventual reclassification as a neoplasm falling short of fully evolved melanoma.