Rheumatoid pleurisy. Specificity of cytological findings.

The cytological findings in pleural exudates from patients with rheumatoid arthritis are epithelioid cells, giant cells, cholesterol crystals and an amorphous granulated material. An important additional feature, we find, is lack of mesothelial cells. Based on 23 pleural fluids from 7 patients with rheumatoid arthritis and 44 pleural fluids from patients with various other diseases, a blind study showed, that these typical cytological findings in combination with lack of mesothelial cells were specific in pointing towards the determined diagnosis rheumatoid pleurisy.