Cloudy Pleural Effusion in a Heavy Smoker With Rheumatoid Arthritis

A 60-year-old male Caucasian, who was a smoker, was referred to the pulmonology clinic because of dyspnea. He also had bilateral arthralgia of the hands and wrists. The patient had a history of rheumatoid arthritis, which was being treated with immunosuppressive drugs. Chest radiography revealed right-sided pleural effusion; thus ultrasound-guided right thoracentesis was performed, resulting in extraction of 1300 mL of cloudy nonmalodorous pleural fluid. Microbiological and cytological analyses were unremarkable, whereas the chemical–physical examination revealed pseudochylothorax. The triglyceride concentration was low, no chylomicrons were detected, and the cholesterol concentration was high. Subsequent chest computed tomography (CT) demonstrated thickened parietal pleura on the right side with a small area of residual pleural effusion, together with right lower lobe segmental atelectasis. The patient underwent medical thoracoscopy, which showed soft yellow peel over the basal parietal pleura. Multiple biopsy specimens were obtained. Microbiology results for the pleural fluid and parietal pleura were negative. Histological examination of biopsy specimens revealed infiltration by inflammatory cells, multinucleated giant cells, and very few mesothelial cells, in a background of amorphous material. No malignant cells or granulomas were detected. The findings were consistent with rheumatoid pleurisy. The patient was started on a new treatment with a selective Janus kinase inhibitor, which led to progressive reduction of rheumatoid arthritis symptoms. At the follow-up, chest ultrasonography and CT showed significant reduction in pleural effusion and lung atelectasis. This chapter provides a comprehensive description of pseudochylothorax and addresses related topics, such as pleural fluid pH measurement and moderate sedation during medical thoracoscopy.