Surgical Margin Mapping of Melanoma In Situ Using In Vivo Reflectance Confocal Microscopy Mosaics.

BACKGROUND: Melanoma in situ (MIS) can have poorly defined borders and subclinical extension that makes margin control challenging. Reflectance confocal microscopy (RCM) is a promising noninvasive technique that can be used to assess subclinical spread. OBJECTIVE: To optimize surgical margins of histology-proven MIS using RCM mosaics. MATERIALS AND METHODS: Prospective review of 22 patients with histology-proven MIS who underwent RCM margin mapping prior to staged excision, between August 1, 2018, and August 13, 2020, at the Department of Dermatology, University of New Mexico, School of Medicine. RESULTS: Twenty patients (91%) had tumor clearance on the first stage using a 3-mm surgical margin after confocal margin mapping. CONCLUSION: Reflectance confocal microscopy margin mapping using the mosaic device tends to clear MIS in one stage, and the use of the handheld device may improve the accuracy for difficult anatomic areas. Current Procedural Terminology codes for RCM do not reflect the time required and complexity of the procedure. Reflectance confocal microscopy margin mapping prior to excision has the potential to decrease the number of stages needed for melanoma removal, reduce treatment time, and cost.