Dynamic dermoscopic and reflectance confocal microscopic changes of melanocytic lesions excised during follow up

Background: Digital dermoscopy follow up (DDF) is useful in improving the recognition of melanoma, catching early changes over time, although benign nevi can also show changes. Reflectance confocal microscopy (RCM) improves accuracy in diagnosing melanoma and decreases the number of unnecessary resections. Objective: To evaluate dynamic dermoscopic and RCM changes during follow up of equivocal melanocytic lesions and assess the impact of adjunctive RCM to DDF for melanoma diagnosis. Methods: A retrospective, multicenter study of extrafacial atypical melanocytic lesions excised during follow up was performed. Morphologic changes were evaluated, comparing dermoscopy and RCM baseline and follow-up images. Results: One hundred thirty-seven atypical melanocytic lesions were studied, including 14 melanomas and 123 benign nevi. Significantly greater changes in DDF of atypical network, regression, atypical streaks, and asymmetrical growth as well as in dynamic RCM of atypical cells and dermal-epidermal junction disarray were noted in melanomas. With adjunctive dynamic RCM and major changes at DDF, sensitivity reached 100%, with 40.6% specificity. Limitations: Selected series of difficult to recognize lesions, with both DDF and dynamic RCM images. Conclusion: Adjunctive dynamic RCM improves early melanoma recognition sensitivity. ( J Am Acad Dermatol 2022;86:1049-57.)