Chylothorax vs. Pseudochylothorax: Cholesterol Crystal Finding in Pleural Effusion.

Chylothorax and pseudochylothorax are both rare forms of pleural effusion characterized by a milky appearance of the pleural fluid. Despite their similarities, they have distinct etiologies, clinical implications, and medical management strategies. Pleural fluid analysis of cholesterol and triglyceride levels is crucial to differentiate between them, establish a proper diagnosis, and guide clinical evaluation and treatment. This case report describes an uncommon presentation of pseudochylothorax associated with long-standing rheumatoid arthritis (RA) in a patient with no prior history of pleural disease.