The dermoscopic island is described as a well-defined area in a melanocytic lesion, with a different dermoscopic pattern from the rest of the lesion. It is predictive of melanoma, particularly when the pattern of the island is atypical. We present the reflectance confocal microscopy (RCM) findings in 3 lesions with dermoscopic islands: nevus-associated melanoma, melanocytic nevus, and in situ melanoma. The nevus-associated melanoma and in situ melanoma presented cellular atypia (atypical cells in isolation or forming nests) and architectural distortion on RCM. The nevus presented an island sign with a typical globular pattern with dense nests and no atypia on RCM. The island sign is mainly associated with in situ and nevus-associated melanomas. RCM offers good cellular resolution to the depth of the reticular dermis and is useful for diagnosing of melanomas presenting a dermoscopic island.

KEYWORDS:Dermoscopic island; Diagnosis; Diagnóstico; Melanoma; Microscopia confocal de reflectancia; Reflectance confocal microscopy; Signo de la isla

PMID: 29173995 

DOI: 10.1016/j.ad.2017.06.018