Musculoskeletal ImagingRheumatoid nodule
a subcutaneous soft tissue swelling of unknown pathogenesis seen frequently in
rheumatoid arthritis. Similar nodules are also seen in various other musculoskeletal disorders, such as
rheumatic fever, collagen diseases,
sarcoidosis,
Weber Christian disease,
gout,
xanthomatosis and various dermatologic and infectious conditions.
In rheumatoid arthritis the nodules are usually are less than 5 cm and are located between the skin and a bony prominence (such as the proximal end of the ulna, the olecranon, and regions about the femoral trochanter and ischial tuberosity). Although they may be freely movable, they may be attached to the deep fascia or peritoneum. Often they are asymptomatic.
On radiographs, rheumatoid nodules appear as lobulated soft tissue masses, rarely calcified. In some cases underlying bone becomes eroded.
DR