Advanced multimodal ultrasound for pre-operative assessment of skin tumours: A case series.

Background: Pre-operative assessment of non-melanoma skin cancers via advanced ultrasound techniques may potentially provide additional information to tumour margins and morphology compared to current assessment via dermoscopy or optical coherence tomography. In this case series, the findings of multimodal ultrasonography of non-melanoma skin cancer are described, with histological correlation.

Methods: Consecutive patients with clinical suspicion of malignant skin lesions underwent multimodal ultrasonography, comprising B-mode, colour Doppler imaging, superb microvascular imaging, strain elastography, and shear-wave elastography, followed by surgical excision. Images were reviewed by two radiologists.

Results: There were 8 female and 3 male patients, whose age ranged from 66 to 98 years. A total of 11 malignant skin tumours (basal cell carcinoma, n = 6; squamous cell carcinoma, n = 5) were reviewed. Tumour depth measured via ultrasound assessment ranged from 1.20 to 7.00 mm (mean ± standard deviation: 4.35 ± 1.99 mm). Tumours were located within dermis (n = 1) and abutting subcutaneous layer (n = 10) sonographically. Where corresponding histological reports for tumour depth were available, ultrasound correlated well with histology. Ultrasound also correctly predicted the deepest layer of involvement for all lesions. The sonographic features observed in all malignant skin tumours (11/11:100%) are solid, hypoechoic, with abundant neovascularity on colour Doppler imaging and superb microvascular imaging, and appeared stiff on strain elastography and shear-wave elastography. In some cases, the microvascular network of intra-tumoural flow were better demonstrated on superb microvascular imaging.

Conclusion: Multimodal ultrasound can potentially be a useful and quick adjunctive tool for the pre-operative assessment of skin cancer by delineating the tumour depth and deepest skin layer involvement, ensuring complete excision of tumour.