Analysis of the dermoscopic features of excised melanomas and their relation with tumor thickness in a tertiary hospital in Brazil

Abstract

Background: Dermoscopy is a non-invasive, cost-effective tool useful in the assessment of pigmented lesions. The aim of this study was to analyze the dermoscopic features in excised melanomas in a tertiary hospital in Brazil and the influence of Breslow thickness on the dermoscopic features observed.

Methods: An observational, cross-sectional study in which dermoscopic images of 43 melanomas were evaluated. The patients were divided into three groups: in situ, thin invasive melanoma (Breslow thickness <1 mm), and thick invasive melanoma (Breslow thickness ≥1 mm).

Results: We studied 33 patients with 43 melanomas. Twenty-one (48.8%) were melanoma in situ, 16 (37.2%) were thin melanomas, and 6 (14%) were thick melanomas. The most frequent dermoscopic criteria observed in all cases were atypical pigment network, multiple colors (3 or more), asymmetrical blotches, and peripheral asymmetric dots and globules. There was a statistically significant difference in the three groups regarding the frequency of atypical vessels, white scar areas, blue-white veil, shiny white structures, and radial streaming. The group of invasive melanomas presented with a higher frequency and statistical significance (P < 0.05) of atypical vessels, white scar areas, blue-white veil, and shiny white structures when compared to in situ melanomas. The presence of radial streaming and blue-white veil was more frequent in thick invasive melanomas than in thin invasive melanomas. The presence of a higher number of structures was seen in invasive melanomas, with a median of 5 and 7.5 structures for thin and thick invasive tumors, respectively.

Conclusions: In line with prior data, we identified an association between invasive melanomas and structures linked to fibrosis and tumor vascularity. Specifically, we noted the presence of atypical vessels, scar-like white areas, a blue-white veil, and shiny white structures. Also, a higher number of dermoscopic structures was seen in invasive melanomas. In thicker melanomas, we observed additional findings, including a higher frequency of radial streaming and a blue-white veil.