Diagnostic performance of Shear Wave Elastography and high-resolution ultrasound in non-melanoma skin cancer: a study of basal and squamous cell carcinomas

Abstract

Aims: This study aimed to evaluate the diagnostic performance of shear wave elastography (SWE) in differentiating non-melanoma skin cancer (NMSC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), from benign skin lesions. A secondary objective was to assess the accuracy of high-resolution ultrasonography (HRUS) for preoperative tumor
measurement.

Material and methods: A prospective study was conducted on 106 patients with clinically suspected NMSC or benign lesions (nevi). Each lesion was evaluated with SWE and HRUS using an 18 MHz probe, followed by surgical excision and histopathological confirmation. Among the confirmed malignancies, 46 were BCC and 15 SCC. The control group included 35 nevi diagnosed clinically and dermatoscopically. SWE stiffness values were compared across lesion types. Tumor length and depth measured by HRUS were validated against pathology using The Student’s t-test or Mann–Whitney U test, Bland–Altman analysis and the Intraclass Correlation Coefficient (ICC).

Results: SWE showed significantly higher stiffness in malignant versus benign lesions, with optimal thresholds of >13 kPa for BCC and >15 kPa for SCC. The area under the receiver operating characteristic curve (AUROC), was 0.95 for BCC and 0.99 for SCC. Differentiation between SCC and BCC was moderate (AUROC=0.70). HRUS accurately estimated tumor length (bias=1.31 mm, p>0.05; ICC=0.90), while depth was slightly overestimated (bias=0.87 mm, p<0.05; ICC=0.83).

Conclusion: SWE and HRUS offer complementary, non-invasive tools for the diagnosis and preoperative assessment of BCC and SCC. SWE demonstrated high diagnostic accuracy for distinguishing NMSC from benign lesions, particularly nevi, by applying stiffness thresholds between 13–15 kPa. HRUS proved effective in estimating tumor length with good agreement to histopathology, though it showed a tendency to overestimate tumor depth.