Melanocytic Skin Lesions Best Interpreted By Experienced, Specialized Pathologists

Pathologists who are board-certified and fellowship-trained in dermatopathology and have ≥5 years of experience provide the most accurate and reproducible interpretations of melanocytic lesions; typical case load composition and volume also influence the accuracy of pathologists’ interpretations.

David E. Elder, MD, and colleagues reported these findings in the Journal of the American Academy of Dermatology.

Two-hundred forty cases of melanocytic lesions, comprising shave, punch, and excisional biopsies, were selected for the study. Each pathologist interpreted 48 cases, classifying their diagnoses using the Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis.

Reproducibility and accessibility were both assessed: reproducibility by concordance of each pathologist’s interpretation over 2 occasions separated by at least 8 months, and accuracy by concordance of each pathologist’s interpretation with a consensus reference diagnosis.

The sample comprised 187 pathologists; only 118 pathologists returned after the 8-month washout period for reinterpretation of the slides. Pathologist characteristics, including level of experience and training, were analyzed in association with these assessments, using multivariable logistic regression modeling.

Significant associations between accuracy and pathologist characteristics were found for the following attributes: dermatopathology board certification and/or fellowship training (odds ratio [OR], 1.41; 95% CI, 1.22-1.63), melanocytic skin lesion case load of 60 or more per month (OR, 1.18; 95% CI, 1.05-1.34), 5 or more years of experience interpreting melanocytic skin lesions (OR, 1.22; 95% CI, 1.04-1.44), and a composition of >10% melanocytic cases in their practice (OR, 1.14; 95% CI, 0.99-1.30).

Significant associations between reproducibility rates and pathologist characteristics were found for the following attributes: dermatopathology board certification and/or fellowship training (OR, 1.37) and 5 or more years of experience interpreting melanocytic skin lesions (OR, 1.41).

“Diagnoses are more accurate among pathologists with specialty training and those with more experience interpreting melanocytic lesions,” the authors wrote. Although the study has its limitations, including application of a classification tool not used in clinical practice, “[t]hese findings support the practice of referring difficult cases to more experienced pathologists to improve diagnostic accuracy, although the impact on patient outcomes of these referrals requires additional research.”

Reference

Elder DE, Piepkorn M, Barnhill RL, et al. Pathologist characteristics associated with accuracy and reproducibility of melanocytic skin lesion interpretation [published online March 7, 2018]. J Am Acad Dermatol. doi: 10.1016/j.jaad.2018.02.070