Rheumatoid pleurisy confirmed by biopsy of a chest wall nodule by thoracoscopy under local anaesthesia.

Rheumatoid pleurisy is common in patients with rheumatoid arthritis, but distinguishing it from other diseases, such as heart failure and tuberculous pleurisy, is often difficult. A man in his 70s with stable rheumatoid arthritis presented with cardiac enlargement and bilateral pleural effusion on chest radiography. Pleural fluid studies showed lymphocytosis, adenosine deaminase level of 51.6 U/L and rheumatoid factor level of 2245.3 IU/mL, suggestive of rheumatoid pleurisy and tuberculous pleurisy. Thoracoscopy under local anaesthesia revealed erythema of the parietal pleura, small papillary projections and fibrin deposits. H&E-stained biopsy specimens showed inflammatory granulomas with strong lymphocytic infiltration and non-caseating granulomas. He was diagnosed with rheumatoid pleurisy. His symptoms improved with 30 mg of prednisolone. This study highlights that biopsy using thoracoscopy under local anaesthesia effectively diagnoses rheumatoid pleurisy, which may be challenging to diagnose.