Variegated dermoscopy of in situ melanoma

Background: Melanomas in situ (MIS) are difficult to diagnose, lacking well-established dermoscopic descriptors.

Objective: The aim of this study was to improve the identification of early melanomas describing the variegated dermoscopic features of MIS and their correlation with demographic and clinical aspects.

Methods: Dermoscopic images of 114 histologically proven MIS were evaluated by 3 expert dermoscopists and classified into their main dermoscopic patterns. Dermoscopic features were also considered for their correlation with clinical parameters.

Results: Eight different dermoscopic subtypes of MIS were identified: reticular grey-blue (27.2%), reticular (21.1%), multicomponent (20.2%), island (10.5%), spitzoid (7%), inverse network (6.1%), 'net-blue globules' (5.3%) and globular (2.6%). Clinical characteristics of lesions and patients varied according to the different dermoscopic groups.

Conclusion: We hypothesize that the different dermoscopic subgroups of MIS correspond to lesions with a different origin and, possibly, various patterns of growth and a different biological behaviour.