Unusual radiological features in Paget's disease of bone.

The radiological diagnosis of Paget's disease of bone is usually straightforward because most cases conform to well-established classic descriptions. Diagnosis becomes more difficult, however, when radiological appearances are not typical or other disease processes mask or alter the behavior of Paget's disease. Examples are presented to illustrate four categories of unusual radiological presentation of Paget's disease: (1) unusual disease progression, (2) massive post-immobilization lysis, (3) metastatic spread to pagetic bone, and (4) vertebral end-plate destruction that mimics infection.