Objective:

To evaluate the diagnostic performance of high-frequency ultrasound (HFUS) combined with superb microvascular imaging (SMI) in differentiating basal cell carcinoma (BCC) from seborrheic keratosis (SK), and to develop a nomogram for individualized probability estimation, emphasizing its non-invasive nature.

Key Findings:

• Significant differences between BCC and SK in age, lesion location, size, depth, morphology, internal echotexture, posterior acoustic features, and microvascular flow patterns (all p < 0.001).
• Independent predictors of BCC included larger tumor size, head location, nodular ultrasound pattern, and random vascular flow.
• The multivariate logistic regression model demonstrated an AUC of 0.861, with sensitivity of 77.55% and specificity of 82.38%.

Interpretation:

HFUS combined with SMI provides a valuable non-invasive approach for differentiating BCC from SK, potentially reducing unnecessary biopsies and facilitating earlier detection of malignant lesions, thereby improving patient outcomes.

Limitations:

• Retrospective design may introduce selection bias, potentially affecting the study's conclusions.
• Limited to a single institution, which may affect generalizability.
• Potential for incomplete data affecting analysis.

Conclusion:

The developed nomogram based on key ultrasound and clinical predictors demonstrates good discriminative performance and offers a practical tool to support clinical decision-making, with implications for future research.