[Pleuropulmonary manifestations of rheumatoid arthritis. A casuistic reminder].

A case of pleuropulmonary manifestations of rheumatoid arthritis (RA) in the form of persistent pleuritis and effusion in a 58 year old male patient with known RA is presented. The well-known pleuropulmonary complications of RA pleurisy, interstitial fibrosis, effusion, rheumatoid nodules and Caplan's syndrome can occur in sero-negative patients without primary articular symptoms and therefore pose difficult problems in differential diagnosis. These problems can be partially overcome by thoracoscopic visualization of the often characteristic changes of the parietal pleura: hyperemia, vasculitis and rheumatoid nodules and histochemical examination of the pleural liquid will show low glucose concentration, high protein concentration, elevated lactate-dehydrogenase concentration, acid pH and a characteristic cytomorphology with mononuclear and neutrophil leucocytes in typical cases. The pleuropulmonary manifestations can sometimes be successfully treated with a combination of NSAIDs and methotrexate.