Malignancies in Rheumatology

Abstract

Several rheumatological disorders are associated with an increased incidence of malignancy as part of the spectrum of their clinical manifestations. These associations are sometimes relatively specific (e.g. primary Sjögren's syndrome with lymphoma) and surrogate markers of malignancy are often helpful in predicting their development (e.g. paraproteinaemia in rheumatoid arthritis (RA)). Malignancy can present with a variety of rheumatological symptoms. These may arise from various organs (bone, muscle, joints, skin, nerves or blood vessels) and diagnosis may be difficult unless an appropriate index of suspicion is maintained. Although these conditions are often unpredictable, there are several specific associations (e.g. hypertrophic osteoarthropathy in lung cancer). Some drugs used in the treatment of RA and other connective tissue disorders are known to lead to an increased risk of malignancy (e.g. bladder and skin with cyclophosphamide, lymphoma and lung with azathioprine). Furthermore, there has been concern that methotrexate might have the potential to induce lymphoma, with regression of lymphoma on methotrexate withdrawal in some cases.