B35-37 Rheumatoid Arthritis: An Unexpected Culprit Behind Cavitary Lung Lesions

Abstract Introduction Rheumatoid arthritis (RA) is often overlooked as a significant contributor to cavitary lung nodules. This case highlights the importance of recognizing RA as a potential cause of multiple cavitary pulmonary lesions, particularly in patients presenting with acute weight loss—a finding more commonly associated with metastatic cancer or infection. Case description A 70-year-old woman with longstanding RA, managed with leflunomide and sulfasalazine, presented with progressive shortness of breath and a 20-pound unintentional weight loss over two months. She also reported a productive cough, dyspnea, and intermittent night sweats but denied hemoptysis or prior malignancy. She had no recent infections or sick contacts but noted possible mold exposure at home.Chest CT revealed multiple enlarging cavitary pulmonary nodules compared with imaging six months earlier. PET-CT demonstrated faint radiotracer uptake, suggesting a benign etiology. Bronchoscopy with biopsy showed no evidence of malignancy, and infectious studies were negative. These findings supported RA as the most likely underlying cause. Discussion RA is a systemic autoimmune disease with a wide spectrum of pulmonary manifestations, including interstitial lung disease, pleural effusions, bronchiectasis, and pulmonary nodules. Cavitary rheumatoid nodules are uncommon but can mimic malignancy or granulomatous infection, often prompting invasive diagnostic workup. Their pathogenesis involves immune-mediated inflammation and necrosis, with potential contribution from disease-modifying antirheumatic drugs such as leflunomide or methotrexate.Management centers on excluding infection, optimizing control of systemic RA, and monitoring disease progression with serial imaging and pulmonary function testing. In symptomatic or progressive cases, corticosteroids or adjustments to the immunosuppressive regimen may be warranted. Given the absence of standardized treatment guidelines, individualized, multidisciplinary care is essential. Conclusions This case emphasizes the need to include RA in the differential diagnosis of cavitary pulmonary nodules, especially when malignancy and infection have been ruled out. Awareness of this manifestation can help prevent unnecessary procedures and guide more appropriate, targeted management. Continued research is needed to better define diagnostic criteria and therapeutic strategies for RA-associated pulmonary disease. This abstract is funded by: No