Dermoscopic Features of Small, Medium, and Large-Sized Congenital Melanocytic Nevi

Background: Congenital melanocytic nevi (CMN) are present at birth. It is well known that the presence of large-sized congenital nevus in early life could predict a major risk of developing melanoma. Objective: To investigate the clinical and dermoscopic features of the CMN, to search for and highlight any differences between small-sized, medium-sized, large-sized CMN. Methods: A nonrandomized observational study was performed. A total of 108 melanocytic nevi were analysed by clinical and dermoscopic examination. Results: Of the subjects, 57.4% were aged less than 16 years, 42.6% were aged 16 and more. Of the nevi, 26 had reticular pattern (24.1%), 35 had globular pattern (32.4%), 13 had reticular-globular pattern (12.0%), 16 had homogeneous pattern (14.8%), 6 had reticular-homogeneous pattern (5.6%), 2 had globular-homogeneous pattern (1.9%), 7 had cobblestone pattern (6.5%), 3 had reticular patchy pattern (2.8%). Atypical dots and globules, focal hypopigmentation and perifollicular hypopigmentation are the most common dermoscopic features of CMN. The rarest dermoscopic feature is the blue-whitish veil. Conclusion: Most of the dermoscopic features related with dysplastic nevi up to the present, such as atypical dots and globules, focal hypopigmentation, perifollicular hypopigmentation were observed in CMN, in our study. Congenital nevus and dysplastic nevi may share the same dermoscopic features, therefore it is important to know it is found at birth or not.