In Vivo Reflectance Confocal Microscopy of Halo Nevus

Background: RCM (reflectance confocal microscopy) is a noninvasive, high-resolution technology that has been proven to improve the diagnostic accuracy over clinical examination in several skin diseases. Objective: The aim of this article is to describe the morphologic features of halo nevi (HN) observed with RCM and correlate them with their dermoscopic characteristics. Method: Nine patients with the clinical diagnosis of HN were assessed with RCM. A second assessment was performed up to 12 months later. Dermoscopic global patterns were obtained and correlated with the RCM findings. Results: In five (55.6%) cases, pagetoid cells were observed. Nonedged dermal papilla and junctional thickening were found in three (33%) cases. Nucleated cells in the dermal papillae and plump bright cells were observed in seven (77.8%) and six (66.7%) cases, respectively. Conclusion: Our study shows that HN observed by RCM can show atypical features that overlap with those observed on atypical melanocytic lesions and malignant melanoma.