Rheumatoid pleuritis, a form of pleural effusion, is an uncommon complication of rheumatoid arthritis, occurring in 2-3% of patients (Walker and Wright, 1967; Naylor, 1990)

Histopathology

Light microscopy reveals replacement of normal cells lining the pleura (mesothelial cells) by a layer of pseudostratified epithelioid cells, multinucleated giant macrophages, and necrotic material (Mandl et al, 1969; Lillington et al 1971)

Clinical Characteristics

Pleural effusion usually occurs in patients previously diagnosed with rheumatoid arthritis, but it can also occur concurrently with or before the development of the joint manifestations of the disease (Graham, 1990; Chou and Chang, 2002). Patients may present with the signs of pleural effusion: dullness on percussion, diminished or absent breath sounds and vocal fremitus, and egophony at the level of the pleural liquid.

Diagnosis

Diagnosis relies on the characteristic cytology of the exudative pleural fluid, which contains elongated and giant multinucleated macrophages in a sea of amorphous granular material. The absence of mesothelial cells is also characteristic (Champion, 1968). While these findings are highly specific for rheumatoid pleuritis (Nosanchuk et al, 1968; Geisinger, 1985; Engel, 1986; Montes, 1988; Shinto, 1988), rheumatoid pleuritis must be considered if more than one of the above cytologic findings are detected.

Treatment

Steroids are the mainstay of treatment for rheumatoid arthritis, and have been shown to improve rheumatoid pleuritis.

References

• Champion GD, Robertson MR, Robinson RG (1968). "Rheumatoid pleurisy and pericarditis". Ann Rheum Dis 27 (6): 521–30.
• Chou CW, Chang SC (2002). "Pleuritis as a presenting manifestation of rheumatoid arthritis: diagnostic clues in pleural fluid cytology". Am J Med Sci 323 (3): 158–61.
• Engel U, Aru A, Francis D (1986). "Rheumatoid pleurisy. Specificity of cytological findings". Acta Pathol Microbiol Immunol Scand [A] 94 (1): 53–6.
• Geisinger KR, Vance RP, Prater T, Semble E, Pisko EJ (1985). "Rheumatoid pleural effusion. A transmission and scanning electron microscopic evaluation". Acta Cytol 29 (3): 239–47.
• Graham WR (1990). "Rheumatoid pleuritis". South Med J 83 (8): 973–5.
• Lillington GA, Carr DT, Mayne JG (1971). "Rheumatoid pleurisy with effusion". Arch Intern Med 128 (5): 764–8.
• Mandl MA, Watson JI, Henderson JA, Wang N (1969). "Pleural fluid in rheumatoid pleuritis. Patient summary with histopathologic studies". Arch Intern Med 124 (3): 373–6.
• Montes S, Guarda LA (1988). "Cytology of pleural effusions in rheumatoid arthritis". Diagn Cytopathol 4 (1): 71–3.
• Naylor B (1990). "The pathognomonic cytologic picture of rheumatoid pleuritis. The 1989 Maurice Goldblatt Cytology award lecture". Acta Cytol 34 (4): 465–73.
• Nosanchuk JS, Naylor B (1968). "A unique cytologic picture in pleural fluid from patients with rheumatoid arthritis". Am J Clin Pathol 50 (3): 330–5.
• Shinto R, Prete P (1988). "Characteristic cytology in rheumatoid pleural effusion". Am J Med 85 (4): 587–9.
• Walker WC, Wright V (1967). "Rheumatoid pleuritis". Ann Rheum Dis 26 (6): 467–74.