Super‐high magnification dermoscopy can add information for the differential diagnosis between melanoma and atypical nevi

Background Dermoscopy is the most used non-invasive imaging technique for the clinical diagnosis of melanoma (MM). Super-high magnification dermoscopy at 400x magnification (D400) has been recently developed and can reveal additional features compared to traditional dermoscopy, up to the identification of single melanocytes in the skin. Objectives To evaluate which structures could be viewed at D400 and to compare them in atypical nevi and MMs. Methods A prospective observational multicenter study was conducted. We enrolled patients who presented atypical melanocytic skin lesions at clinical and/or 20x dermoscopy examination, assigned to either excision or follow-up. Lesions were imaged by videodermoscopy at 20x and 400x magnification. The presence of pigmented cells and their features were assessed at D400. Results We included 79 patients with 57 nevi and 31 MMs. 63 (71.6%) lesions had a histological diagnosis and the others did not show any change at ≥12 month-follow-up and were all diagnosed as nevi. Pigmented cells were identified in more than 90% of the lesions at D400. MMs showed more frequently than nevi pigmented cells that were dendritic or roundish, violet or blue, large, scattered, irregular in shape and size at D400 (p Conclusions This study showed that D400 can reveal many elements not otherwise visible in traditional 20x dermoscopy, such as pigmented cells and their morphology, that could be useful for the diagnosis of MM.