The dual association between lymphoma and autoimmunity.

Autoimmune rheumatic diseases and lymphocytic malignancies are related and this association is bidirectional. Lymphomas occur more frequently in the course of autoimmune disease and autoimmune rheumatic manifestations occur in the course of lymphocytic malignancies. An increased incidence of malignant lymphocytic diseases is present in patients with rheumatoid arthritis, systemic lupus erythematosus, Sjögren's syndrome, and autoimmune thyroid disease. Descriptions of lymphocytic malignancies among other autoimmune rheumatic disease have been published. In some patients, the malignant disease is diagnosed months or years before the appearance of the rheumatic disease.