Pulmonary necrobiotic nodules without rheumatoid arthritis.

Pulmonary necrobiotic nodules are the least common of the pulmonary lesions associated with rheumatoid arthritis. Histologically they are identical to subcutaneous rheumatoid nodules. Systemic rheumatoid arthritis usually precedes the development of pulmonary nodules. Seven cases where the pulmonary nodule appeared before or without the development of systemic rheumatoid arthritis are described. The typical histological and radiological features of necrobiotic nodules were found in each. In five of the seven the nodules were in more than one site and in five there were cavitating nodules. Spontaneous improvement occurred in one case. Pulmonary nodules preceded systemic rheumatoid arthritis in three cases and in the remaining four cases systemic rheumatoid arthritis has not yet appeared despite prolonged follow-up. In all patients, tests for rheumatoid factor have remained negative. The absence of circulating rheumatoid factor and systemic rheumatoid arthritis cannot exclude the diagnosis in these cases if the histological diagnosis is accepted as conclusive.