How I do it: ultrasound evaluation of peripheral nerve tumors and their mimics

With the availability of high-frequency ultrasound and magnetic resonance imaging, the diagnosis of peripheral nerve tumors has become both feasible and highly accurate. The central clinical question has shifted from simple identification to management, specifically whether a lesion should be surgically removed, monitored, or left untreated. In this paper, we outline a practical and clinically relevant approach to the evaluation of peripheral nerve tumors using ultrasound and magnetic resonance imaging, focusing on reproducible technique, key imaging hallmarks, and common diagnostic pitfalls. Ultrasound enables dynamic, high-resolution evaluation of nerve continuity, fascicular pattern, and vascularity, while magnetic resonance imaging delineates deep-tissue extent and internal architecture. A combined, stepwise interpretation allows radiologists and surgeons to differentiate schwannoma, neurofibroma, and malignant peripheral nerve sheath tumor from mimicking lesions such as ganglion cysts, tenosynovial giant cell tumors, lipomatosis of nerve, and synovial sarcoma. Our goal is to illustrate how targeted ultrasound, complemented by magnetic resonance imaging, can support a confident imaging-based diagnosis of peripheral nerve tumors, particularly schwannomas, and provide a framework for clinical assessment.