Estimating the potential impact of interventions to reduce over‐calling and under‐calling of melanoma

Abstract

Pathologists sometimes disagree over the histopathologic diagnosis of melanoma. ‘Over‐calling’ and ‘under‐calling’ of melanoma may harm individuals and healthcare systems.

The objective of this study was to estimate the extent of ‘over‐calling’ and ‘under‐calling’ of melanoma for a population undergoing one excision per person and to model the impact of potential solutions.

In this epidemiological modelling study, we undertook simulations using published data on the prevalence and diagnostic accuracy of melanocytic histopathology in the U.S. population. We simulated results for 10 000 patients each undergoing excision of one melanocytic lesion, interpreted by one community pathologist. We repeated the simulation using a hypothetical intervention that improves diagnostic agreement between community pathologist and a specialist dermatopathologist. We then evaluated four scenarios for how melanocytic lesions judged to be neither clearly benign (post‐test probability of melanoma < 5%), nor clearly malignant (post‐test probability of melanoma > 90%) might be handled, before sending for expert dermatopathologist review to decide the final diagnosis.