Discordance in the histopathologic diagnosis of difficult melanocytic neoplasms in the clinical setting

Background: The gold standard for diagnosing melanocytic neoplasms is by histopathologic examination. However, lack of agreement among expert dermatopathologists in evaluating these tumors has been well established in experimental settings. Objective: This study examines the discordance among dermatopathologists in evaluating difficult melanocytic neoplasms in a clinical setting where the diagnosis impacts patient management. Methods: Retrospective review of consultation reports over a 6-year period. Results: There was complete agreement among the consultants in 54.5% of the cases. However, a high level of disagreement was found in 25% of the cases. Limitations: The analysis was limited to two consultant dermatopathologists. Conclusions: There are limitations to the practical applications of histologic criteria for diagnosing difficult melanocytic tumors. It is not malpractice for a pathologist to have rendered a diagnosis that did not predict clinical outcome as long as 'standard of care' has been followed in his/her evaluation of the specimen.