Clinical Edge

Summaries of Must-Read Clinical Literature, Guidelines, and FDA Actions

Pathology Methods for Melanocytic Lesions Compared

JAMA Dermatology; ePub 2018 Aug 15; Onega, et al

Interpretive accuracy for melanocytic lesions was similar for whole-slide imaging (WSI) and traditional microscopy (TM) slides except for class III lesions. This according to a recent study that aimed to compare pathologists’ accuracy and reproducibility in diagnosing melanocytic lesions using Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis (MPATH-Dx) categories when analyzing by TM vs WSI. A total of 87 pathologists in community-based and academic settings from 10 US states were randomized with stratification based on clinical experience to interpret in TM format 180 skin biopsy cases of melanocytic lesions, including 90 invasive melanomas, divided into 5 sets of 36 cases (phase 1). They found:

  • Except for class III melanocytic lesions, the diagnostic categories showed no significant differences in diagnostic accuracy between TM and WSI interpretation.
  • Discordance was lower among class III lesions for the TM interpretation arm (51%) than for the WSI arm (61%).
  • This difference is likely to have clinical significance, because 6% of TM vs 11% of WSI class III lesions were interpreted as invasive melanoma.


Onega T, Barnhill RA, Piepkorn MW, et al. Accuracy of digital pathologic analysis vs traditional microscopy in the interpretation of melanocytic lesions. [Published online ahead of print August 15, 2018]. JAMA Dermatology. doi:10.1001/jamadermatol.2018.2388.