Etanercept-related extensive pulmonary nodulosis in a patient with rheumatoid arthritis

Although nodulosis is a common extraarticular manifestation of rheumatoid arthritis, accelerated pulmonary nodulosis is a rare event. The etiology of rheumatoid nodules is still unknown. Nodulosis is not necessarily associated with active joint inflammation, suggesting different pathogenic mechanisms for nodule formation and synovial tissue inflammation. We describe a patient with extensive pulmonary nodulosis, probably related to etanercept treatment. Our case emphasizes the need for careful monitoring for adverse events during treatment with biologicals, especially since the differential diagnosis often includes a broad spectrum of diseases.