What is the impact of tumour size on dermoscopic diagnosis of BCC?

Background The effect of size on diagnostic performance of dermoscopy in basal cell carcinomas (BCCs) is yet to be determined. Objectives To investigate the differences in dermoscopic features between small- and large-sized BCCs. Methods A total of 151 BCCs consecutively collected during a 2-year period were analysed. These tumours were evaluated for the presence of various dermoscopic features (colours, structures and vessels) using the contact polarized dermoscopy. Differences in proportions were evaluated by means of chi-squared test and Fisher's exact test, when appropriate. Results In all, 62 (41.1%) small (<= 1 cm) and 89 (58.9%) large (> 1 cm) BCCs were included. Arborizing vessels, short fine telangiectasias (SFT) and multiple small erosions were significantly (P < 0.05) more frequent in the group of large BCCs. Further analysis of the effect of size on dermoscopic features within the specific groups, nodular, superficial and ulcerated, found significant difference only in the group of nodular BCCs. Structureless hypopigmentation was significantly (P < 0.05) more frequent in the group of large nodular BCCs in comparison with the small ones. Conclusions Despite determined differences in vascular features and multiple erosions between the small and large BCCs, the results of further investigation within the specific groups indicate that dermoscopy is reliable for the diagnosis of BCC regardless of its size.