Acute Exacerbation of Rheumatoid Arthritis-Associated Interstitial Lung Disease After Thoracic Surgery in the Absence of Usual Interstitial Pneumonia Pattern on CT.

The usual interstitial pneumonia (UIP) pattern observed on chest computed tomography (CT) is considered a risk factor for the development of postoperative acute exacerbation in interstitial lung disease (ILD). However, the risk factors for acute exacerbation in patients with rheumatoid arthritis (RA)-associated ILD have not been adequately investigated. We present a case of postoperative acute exacerbation after thoracic surgery in a 73-year-old man with RA-ILD and non-UIP pattern on chest CT. This case report emphasizes that postoperative acute exacerbation can develop even in the absence of a radiological UIP pattern.