a case of infarcted localized tenosynovial giant cell tumor of the knee: multimodality imaging features and literature review

Localized tenosynovial giant cell tumor (l-tgct), formerly called giant cell tumor of the tendon sheath, is one of the benign proliferative diseases of the synovium of a joint, bursa, or tendon sheath. l-tgct occasionally involves a large joint such as the knee, and rarely it is combined with infarction by pedicle torsion. neither the prevalence of torsion of l-tgct nor the mechanism involved are known, but it is thought to be uncommon progress. herein, we describe a rare case of infarcted l-tgct in the knee involving torsion of a mass pedicle in a 47-year-old man. we utilized magnetic resonance imaging including diffusion-weighted imaging and axial apparent diffusion mapping, and sonographic appearance during the course of investigations, because radiologic findings showed characteristic features of infarcted l-tgct.