Reflectance confocal microscopy terminology for nonmelanocytic skin lesions: A Delphi consensus of experts

Background: There is lack of uniformity in reflectance confocal microscopy (RCM) terminology. Objective: To establish expert consensus on a standardized set of RCM terms that describe non-melanocytic lesions (NMLs). Methods: We invited RCM experts to participate in a Delphi-consensus study. Fifty-nine RCM descriptors were extracted from a previous systematic review on RCM terminology for describing NML. Of these, 35 items were presented as 4 groups of synonymous terms and 24 items as single, nonsynonymous terms. For the first round, an agreement threshold was set at >70%. Participants could also propose new terms. Terms with ≤70% agreement and newly proposed terms were carried over to the next round. For subsequent rounds, agreement threshold was set at >50%. Results: The study was conducted between June 2021 and May 2023. Forty-two of 44 (95%) invited experts participated. Three iterative Delphi rounds were completed, resulting in a consensus list of 36 terms, including 32 synonymous and 4 nonsynonymous terms for describing NML. Limitations: Only experts were included. We did not evaluate definitions of terms in the study. Conclusions: We propose a simplified list of RCM terms, vetted by RCM experts, for describing and diagnosing NML. Uniform terminology could benefit clinical practice, research, and education.