Evaluation of the Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis (MPATH-Dx) classification scheme for diagnosis of cutaneous melanocytic neoplasms: Results from the International Melanoma Pathology Study Group

Abstract

Background Pathologists use diverse terminology when interpreting melanocytic neoplasms, potentially compromising quality of care. Objective To evaluate the Melanoma Pathology Assessment and Treatment Hierarchy (MPATH-Dx) scheme, a five-category classification system for melanocytic lesions. Methods Participants (n=16) of the 2013 International Melanoma Pathology Study Group Workshop provided independent case-level diagnoses and treatment suggestions for 48 melanocytic lesions. Individual diagnoses (including, when provided, least and most severe diagnoses) were mapped to corresponding MPATH-Dx classes. Inter-rater agreement [95% CI] and correlation between MPATH-Dx categorization and treatment suggestions were evaluated. Results Most participants were dermatopathologists (n=12), age ≥50 years (n=12), male (n=9), US-based (n=11), and primary academic faculty (n=14). Overall, participants generated 634 case-level diagnoses with treatment suggestions. Mean weighted kappa coefficients for diagnostic agreement following MPATH-Dx mapping (assuming least and most severe diagnoses, when necessary) were 0.70 [0.68, 0.71] and 0.72 [0.71, 0.73], respectively, while correlation between MPATH-Dx categorization and treatment suggestions was 0.91. Limitations Small sample size of experienced pathologists in a testing situation. Conclusion Varying diagnostic nomenclature can be consistently classified into a concise hierarchy using the MPATH-Dx scheme. Further research is needed to determine whether this classification system can facilitate diagnostic concordance in general pathology practice and improve patient care.

Accuracy of tele‐consultation on management decisions of lesions suspect for melanoma using reflectance confocal microscopy as a stand‐alone diagnostic tool

“…These limitations have led to a recent concerted effort to create a simplified, clinically relevant ontology of histopathological diagnosis of melanocytic tumours termed M-Path. 15,16 However, even with this simplified schema, interobserver agreement for 'type 3' lesions (e.g. melanoma in situ) among experienced pathologists was 40%.…”

“…While if taken at face value, the diagnostic accuracy and interobserver agreement in our study seems concerning, it is important to note that the gold standard of histopathology that we applied has its own limitations. These limitations have led to a recent concerted effort to create a simplified, clinically relevant ontology of histopathological diagnosis of melanocytic tumours termed M‐Path . However, even with this simplified schema, interobserver agreement for ‘type 3’ lesions (e.g.…”

Variation among pathologists' treatment suggestions for melanocytic lesions: A survey of pathologists

“…Treatment recommendations may be more consistent when pathologists are examining actual slides as compared with our study. 18,19 Further, the treatment options on the MPATH survey are not always reflective of everyday practice for pathologists. 19 Pathologists were limited to choosing from limited options for treatment recommendations.…”

Re: Deep learning outperformed 11 pathologists in the classification of histopathological melanoma images

“…Borderline lesions exist which cannot be unequivocally designated as melanoma or nevus [5]. Omitting such cases from the analysis and using binary choices instead of more sophisticated classifications such as the MPATH-DX (Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis) [6] or World Health Organisation [7] scheme may simplify study design and facilitate training of artificial intelligence. However, it does not reflect the current state of classification and makes application to unselected melanocytic lesions encountered in routine practice impossible.…”