Pseudochylothorax without pleural thickening: time to reconsider pathogenesis?

Pseudochylothorax (cholesterol pleurisy or chyliform effusion) is a cholesterol-rich pleural effusion that is commonly associated with chronic inflammatory disorders such as tuberculosis or rheumatoid arthritis. Until now, there were only 15 published cases of arthritis-associated pseudochylothorax in the English language literature. Previous literature has suggested that pleural fluid cholesterol enrichment occurs in the context of grossly thickened (fibrotic) pleura over a prolonged period, usually > 5 years. We present six well-characterized cases of arthritis-associated pseudochylothorax, each notable due to their minimal pleural thickening. The median duration of symptoms (or arthritis, in the case of asymptomatic effusions) was 15 months. Such findings cast significant doubt on the conventional concepts of the pathogenesis of rheumatoid-associated pseudochylothorax. Clinicians should consider pseudochylothorax even in short-duration nonfibrotic pleural effusions.