Confocal laser microendoscopy characterization of vascular features in facial basal cell carcinoma: a comparative analysis of tumor and adjacent healthy tissue.

An initial application of Confocal laser microendoscopy (CLE) in basal cell carcinoma (BCC) was promising, yet data in this field are still limited. Tumor vasculature, which can be clearly visualized by CLE, differs significantly from that of normal tissue, but has not yet been systematically analyzed as a target of CLE in BCC. By systematically assessing vascular features, we aim to define diagnostic criteria that support a more standardized and objective use of CLE in BCC. CLE imaging was performed in nine patients with histologically confirmed facial BCC. Forty artifact-free vascular sequences (20 BCC, 20 healthy skin) were analyzed using five predefined criteria independently rated by three blinded reviewers. Diagnostic accuracy, sensitivity, specificity, and interrater agreement were calculated. Normal skin showed regular, well-defined, round vessels of uniform size, whereas BCC demonstrated heterogeneous, dilated, and elongated vessels with indistinct borders and variable flow. Mean sensitivity and specificity were 91.7 ± 4.7% and 86.7 ± 6.2%, respectively, with substantial interrater agreement (κ = 0.77). Vascular features in CLE sequences supported the differentiation between BCC and healthy skin. Incorporating vascular criteria into CLE-based scoring systems appears promising for a more standardized differentiation of BCC from healthy skin. Further studies with larger patient cohorts are warranted to validate these preliminary findings and assess their clinical applicability. Not applicable, as this study is a retrospective analysis.