Experts Publish Consensus Statement on Classification System for Pathology and Diagnosis of Melanocytic Lesions

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In recognition of continuing issues with the process of melanocytic pathology assessments, an expert panel of three dermatopathologists—with assistance from an expert team of researchers—has developed and now revised the Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis schema (MPATH-Dx), a classification system designed to be utilized by pathologists and clinicians worldwide for increased clarity in reporting, according to a new consensus statement published by Barnhill et al in JAMA Network Open.


With the growing number of skin biopsies performed annually for suspected melanoma, a simple, easily understood, standardized classification system for melanocytic lesions may be increasingly important to aid pathologists and clinicians who examine millions of tissue samples each year—and to alleviate patient confusion and anxiety.

Skin biopsies, particularly those suspected to be positive for melanoma, are some of the most complicated for pathologists to diagnose. Furthermore, pathology reports for skin biopsies are often filled with varied and complicated medical terms that can make a diagnosis or treatment plan unclear for medical providers. With increased access to medical records and other digital resources, patients now share in the confusion and growing unease when reading their own skin biopsy reports. 

MPATH-Dx Schema Version 2.0 and Methodology

The updated MPATH-Dx schema Version 2.0 may offer simplified diagnoses of all biopsied melanocytic skin lesions into four classes ranging from MPATH-Dx class I benign low-risk lesions—such as banal nevi—to much higher-risk class IV thick invasive melanoma cases requiring appropriate surgical removal and consideration of additional evaluation for tumor spread as well as more advanced treatments and surveillance. Therefore, the MPATH-Dx schema Version 2.0 may provide suggested guidance on how to best treat patients for each of the four classes.

The investigators examined and made improvements to the original MPATH-Dx schema by incorporating feedback from dermatopathologists participating in a National Institutes of Health–funded study and from members of the International Melanoma Pathology Study Group.


“Pathology reports can be confusing for both patients and primary care physicians. This new tool will help provide clarity in what the pathology diagnosis is to these end users, along with simple guidance on the risk level of the lesion and appropriate treatment,” highlighted senior study author Joann G. Elmore, MD, MPH, Professor of Medicine at the David Geffen School of Medicine as well as Professor of Health Policy and Management at the Fielding School of Public Health at the University of California, Los Angeles. “In the past, primary care physicians might biopsy a patient’s suspicious-looking skin lesion and receive a pathology report that states: ‘junctional dysplastic nevus with low-grade atypia.’ [T]he primary care physician might not know what this means for the patient regarding underlying risk of melanoma and what, if any, additional treatment or surveillance is best for this patient. When pathologists use the MPATH-Dx schema as an adjunct tool, the pathology report would include additional summary information stating ‘MPATH-Dx Class I, no further treatment required,’ thus reducing provider confusion and patient anxiety.”

In summary, the primary aim of the new assessment schema and revision is to have a robust adjunct tool available to support pathologists that can be used for standardizing diagnostic reporting of melanocytic lesions and recommended management to the benefit of both health-care providers and patients.

Disclosure: The research in this study was supported by grants from the National Cancer Institute, the National Health and Medical Research Council of the Australian Government, the Melanoma Research Alliance, and the Department of Defense. For full disclosures of the study authors, visit

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.