title: Rheumatoid pleural effusion presenting as pseudochylothorax in a patient without previous diagnosis of rheumatoid arthritis.
abstract: BACKGROUND
  Rheumatoid pleurisy rarely occurs before a diagnosis of rheumatoid arthritis (RA). It is the second leading cause of pseudochylothorax, but there are few reports of RA-associated pseudochylothorax.
  
  
  METHODS
  A 50-year-old man presented to our hospital with an undiagnosed exudative pleural effusion. In order to obtain a definitive diagnosis, we performed medical thoracoscopy under local anesthesia. The pleural effusion was turbid and was identified as a pseudochylothorax. The parietal pleura was white and slightly thickened with numerous scattered small granules and the pleural biopsy showed an infiltration of inflammatory cells including lymphocytes and plasma cells with a lack of normal mesothelial cells, findings that were highly consistent with rheumatoid pleurisy. Additional laboratory data revealed elevated levels of CCP antibody and rheumatoid factor. During an outpatient visit about 30 days after discharge, the patient complained of polyarthralgia and was diagnosed with RA, resulting in a definitive diagnosis of the pleural effusion as rheumatoid pleurisy.
  
  
  CONCLUSIONS
  We encountered a rare case of a rheumatoid pleural effusion without other symptoms of arthritis, which was identified as a pseudochylothorax by medical thoracoscopy.
authors.affiliation: Department of Surgery, Tokyo Metropolitan Hiroo General Hospital, 2-34-10 Ebisu, Shibuya-ku, Tokyo 150-0013, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Yokosuka
authors.affiliation: Department of Respiratory Medicine, Tokyo Metropolitan Hiroo General Hospital, Japan.
authors.forename: Asako
authors.initials: A
authors.lastname: Suda
authors.affiliation: Department of Respiratory Medicine, Tokyo Metropolitan Hiroo General Hospital, Japan.
authors.forename: Midori
authors.initials: M
authors.lastname: Sugisaki
authors.affiliation: Department of Respiratory Medicine, Tokyo Metropolitan Hiroo General Hospital, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Respiratory Medicine, Tokyo Metropolitan Hiroo General Hospital, Japan.
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Narato
authors.affiliation: Department of Respiratory Medicine, Tokyo Metropolitan Hiroo General Hospital, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Saito
authors.affiliation: Department of Respiratory Medicine, Tokyo Metropolitan Hiroo General Hospital, Japan.
authors.forename: Tatsuji
authors.initials: T
authors.lastname: Enomoto
authors.affiliation: Department of Surgery, Tokyo Metropolitan Hiroo General Hospital, 2-34-10 Ebisu, Shibuya-ku, Tokyo 150-0013, Japan.
authors.forename: Toshiko
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Department of Respiratory Medicine, Tokyo Metropolitan Hiroo General Hospital, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Nomura
keywords: Medical thoracoscopy; Pseudochylothorax; Rheumatoid arthritis; Rheumatoid pleurisy