Ultrasound of skin cancer: what we need to know.

Ultrasound is an imaging technique that can provide critical anatomical information about malignant skin tumors that cannot be deducted by clinical examination, dermoscopy, or even biopsy. This data can support detecting and assessing the extent of the primary tumor and its differential diagnosis, surgical planning, and locoregional staging. Moreover, this non-invasive technique can help to follow-up and detect recurrences. This review aims to address the most common indications for ultrasound in skin oncology and provide a comprehensive guide to the grayscale and color-Doppler findings in cutaneous melanoma, squamous cell carcinoma, basal cell carcinoma, and other cutaneous malignant tumors.