Dermoscopy guided high-frequency ultrasound features of basal cell carcinoma subtypes compared with histopathology: a multicenter study

Abstract Accurate non-invasive differentiation of basal cell carcinoma (BCC) subtypes is crucial for guiding treatment; however, current imaging tools have limitations in accessibility, depth resolution, and interpretability. To describe sonographic features of distinct BCC subtypes using dermoscopy-guided high-frequency ultrasound (DG-HFUS), and assess its potential as a non-invasive subtyping modality. In this multicenter cross-sectional study, 87 histologically confirmed BCCs (nodular, superficial, infiltrative, and micronodular) were imaged using a portable 33 MHz DG-HFUS device. Morphological features were evaluated independently by blinded observers, and statistical associations with histologic subtypes were analyzed using univariate logistic regression. Hypoechoic mass was the most common sonographic feature of BCCs, seen in 92% of cases. Distinct DG-HFUS features correlated with specific subtypes: ribbon-like shape (OR = 86.3, p < 0.0001), homogeneous internal echoes (OR = 22.5, p = 0.003), and well-defined margins (OR = 9, p = 0.04) were strongly associated with superficial BCC; oval shape (OR = 3.8, p = 0.003) and prominent hyperechoic spots (OR = 3.5, p = 0.005) with nodular BCC; and acoustic shadowing (OR = 7.5, p = 0.001) with infiltrative BCC. Micronodular BCCs were underrepresented. Mixed subtypes were excluded, and vascular patterns were not evaluated. DG-HFUS reveals subtype-specific sonographic features and offers a promising, accessible, and interpretable tool for non-invasive BCC classification in clinical settings.