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 herein. 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 in the management of patients. Version 2.0 also has clearly defined histopathological criteria for classification of Class I and II lesions 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 WHO 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.