Non-Hodgkin's lymphoma of the synovium simulating rheumatoid arthritis.

Skeletal involvement in patients with non-Hodgkin's lymphoma (NHL) is common, although direct involvement of the joints is unusual. We describe 2 adults who presented with features suggestive of a diagnosis of rheumatoid arthritis, but who were found to have diffuse NHL of the synovium. Results of a review of the literature, and assessment of the few similar cases in which NHL presented in the joint, suggest that the lymphoma may mimic either a monarticular or polyarticular synovitis, without lymphadenopathy or hepatosplenomegaly. Radiographic demonstration of associated bone destruction is the best evidence for non-Hodgkin's lymphomatous arthropathy in patients with rheumatic symptoms.