Synovitis in secondary syphilis. Clinical, light, and electron microscopic studies.

Polyarthritis and tenosynovitis were seen as the presenting complaints in 7 patients with secondary syphilis. Synovial needle biopsy was obtained in 3 cases and showed mild synovitis with infiltration by lymphocytes, plasma cells, and polymorphonuclear leukocytes; vascular congestion; and slightly increased synovial lining cells. In addition, electron microscopy in these synovial membranes showed many necrotic polymorphonuclear leukocytes, much interstitial debris and fibrin, and in 2 patients, bodies suggestive of Treponema pallidum in the interstitium and in vessel lumens.