Ultrasound of tumors and tumor-like lesions of the foot and ankle

Soft-tissue masses and pseudotumoral lesions are commonly assessed in routine ultrasonography, either because they represent the primary indication for imaging or because they are discovered incidentally during examinations performed for unrelated clinical reasons. Ultrasound is particularly well suited for their assessment, offering several advantages, including real-time correlation with physical findings and clinical history, low cost, excellent spatial and contrast resolution, Doppler evaluation, and direct comparison with the contralateral side. The annual incidence of soft-tissue tumors is estimated at approximately 3 per 1,000 inhabitants, with benign lesions accounting for nearly 99% of cases and lipomas being the most frequent. In many patients, ultrasonography enables a confident diagnosis and helps determine whether further evaluation with magnetic resonance imaging or percutaneous biopsy is required. The predominantly superficial anatomy of the foot and ankle makes these regions especially accessible to high-frequency ultrasound. The technique is particularly valuable for assessing superficial masses smaller than 5 cm. Familiarity with the sonographic appearance of the different soft-tissue tumors, together with an understanding of the advantages and limitations of ultrasonography, is essential for radiologists. Accurate interpretation improves diagnostic precision and reduces the risk of inadequate management, particularly when potentially malignant lesions are encountered.