Carcinoma polyarthritis: role of immune complexes in pathogenesis.

Rapid onset of an additive inflammatory arthritis was observed in a patient with newly-diagnosed carcinoma of the lung. Serological studies revealed antinuclear antibodies and evidence of circulating immune complexes (CIC) by Raji cell assay. Synovial fluid was inflammatory and synovial biopsy showed chronic synovitis, but immunofluorescence and electron microscopy of tumor and synovium failed to reveal evidence of immune complex deposition. These findings suggest that CIC may not be the cause of carcinoma polyarthritis.