The association between the morphology of vessels in primary cutaneous melanoma on dermoscopy, with the Breslow index, the presence of ulceration, and the dermoscopic signs of extensive regression.

BACKGROUND Dermoscopy is a noninvasive technique for the diagnosis of cutaneous melanoma that may play a role in the preoperative assessment of melanoma thickness. With this technique, several vascular morphologies have been identified. The objectives of this study are to study the presence and morphology of blood vessels in a series of primary melanomas and to investigate whether they are related to the Breslow index, the presence of ulceration, and extensive dermoscopic regression. METHODS This cross-sectional study included non-acral, non-facial primary melanomas, with dermoscopic images from four hospitals in Spain. The outcome variables were: the Breslow index, the presence of dermoscopic ulceration, and an extensive dermoscopic regression. The explicative variables were: the presence of vessels, the predominant vessel in the most raised area of the melanoma, and the presence of polymorphous vessels. To study the association between qualitative variables and the Breslow index we used the Kruskal-Wallis test or Mann-Whitney U test, and between qualitative variables, the Chi-square test. To study the magnitude of the association, the ORs (95% CI) were calculated. RESULTS A set of 516 images from melanomas was collected. The presence of vessels was associated with thicker melanomas (p<0.001). Vessel type was associated with different Breslow indexes (p<0.001) (arborizing, linear irregular, corkscrew, glomerular, hairpin, and dotted vessels (in decreasing order)). The polymorphous vessels were associated with thicker melanomas (p<0.001). Linear irregular vessels were associated with ulceration (OR =10.6, 95% CI (4.9-24.0), (p<0.001)) and dotted vessels with the presence of extensive dermoscopic regression (OR=2.7, 95% CI (1.4-5.2), (p=0.003)). The main limitations of this study were the high selection of cases and the difficulty in identifying vessels in pigmented melanomas by dermoscopy. CONCLUSIONS The morphology of blood vessels in cutaneous melanoma on dermoscopy is associated with the Breslow index, the presence of ulceration, and extensive dermoscopic regression.