T2-weighted Hypointense Tumors and Tumor-like Lesions.

Most musculoskeletal tumors are hyperintense on T2-weighted images. However, some T2-weighted hypointense tumors and tumor-like lesions are encountered in everyday clinical practice. We explore the spectrum of such T2 hypointense tumors and tumor mimickers that can arise from (1) the bones, presenting as diffuse processes or focal lesions; (2) the joints including diffuse or focal synovial disorders, loose bodies, or substance depositions; and (3) soft tissues, comprising T2 hypointense tumors and tumor mimickers (those that contain abundant fibrous tissue, mineralization, or hemosiderin deposits). Appropriate magnetic resonance imaging sequence selection is required to identify and characterize these lesions confidently when imaging musculoskeletal tumors.