Dermoscopy of Naevus-associated Melanomas

In order to determine dermoscopic parameters, a case-control test set of naevus-associated melanomas vs de novo melanomas paired by Breslow thickness and histopathological subtype was analysed by 2 blinded experienced dermoscopists, according to presence of naevus, pattern analysis and ABCD dermoscopy score. The ability to identify naevus-associated melanomas by pattern analysis was low for both blinded dermoscopists (kappa<0.2). Dermoscopy features associated with naevus-associated melanomas were: presence of negative pigment network (OR 9.915, CI 95% 2.182-45.049), globules (OR 2.383, CI 95% 1.15-4.95) and streaks (OR 2.439, CI 95% 1.271-4.680). In contrast, the presence of blue-white veil was related to absence of associated naevus (OR 0.520, CI 95% 0.273-0.991). With the results obtained, 2 different algorithms were proposed. The use of the proposed algorithms could help raise awareness of naevus-associated melanomas and avoid the possibility of incorrectly diagnosing a naevus-associated melanoma if partial biopsies are performed.