Synovial calcification in a patient with collagen-vascular disease: light and electron microscopic studies

Unusual articular as well as periarticular calcifications are reported in a patient with collagen-vascular disease. Tiny crystals visible in electron micrographs in synovial membrane and in synovial fluid cell vacuoles resemble apatite and appear most consistent with apatite on electron probe studies. The inflammatory synovial effusion also contained chylomicrons. Other joint diseases associated with synovial calcification or suspected synovial apatite are discussed.