Dermoscopy of small melanomas: just a miniaturized dermoscopy?

BACKGROUND AND OBJECTIVE: Small melanomas (MMs) are usually MMs in an initial growth phase, deserving attention by the clinician aiming at an early diagnosis. The aim of this study was to identify clues for early diagnosis of small MM, by comparing the dermoscopic features of MMs smaller than 4 mm (micromelanomas) to those of larger MMs. MATERIALS AND METHODS: The database consisted in the dermoscopic images of 482 MMs which were retrieved and measured digitally. The ABCD and the 7-point criteria were evaluated on the whole data base by 3 expert dermoscopists, whereas the main dermoscopic pattern was assessed only on micromelanomas. The dermoscopic aspects were correlated to clinical and histological ones. RESULTS: Most 7-point and ABCD scores and criteria referring to micromelanomas differed from those of the whole MM data base. Lesion asymmetry, number of colors, blue-whitish veil, atypical vessels, irregular globules/dots and regression increased according to MM diameter. An inverse trend was observed for atypical network and irregular pigmentation, which were more frequently observed in micromelanomas than in larger ones. Among the 22 micromelanomas, 12 lesions were in situ, whereas the other 10 were 0.2-2 mm thick. The clinical and dermoscopic characteristics of the 2 groups were similar. CONCLUSIONS: Micromelanomas are not a rarity. However, the clinician should be aware of the fact that the majority of them lack most of the dermoscopic features presented by larger lesions. This article is protected by copyright. All rights reserved.