Mimics of bone and soft tissue neoplasms.

Many benign nonneoplastic entities can mimic bone and soft tissue tumors on imaging examinations. Distinguishing between neoplastic and nonneoplastic entities depends on history and physical examination findings and imaging findings, and is an important early step in the patient's overall workup and treatment plan. This article describes some of the pseudotumors seen on imaging studies in our orthopedic oncology clinic, as well as mimics of bone and soft tissue neoplasms described in the medical literature. Tumor mimics resulting from anatomic and developmental variants, trauma, infection and inflammation, osteonecrosis and myonecrosis, articular and juxta-articular conditions, and miscellaneous causes are discussed.