title: Microcirculatory changes in posttraumatic pigmented villonodular synovitis.
abstract: The synovium from a case of pigmented villonodular synovitis was examined by light and electron microscopy. The hyperplastic villous processes were found to contain, besides many blood vessels, a dense population of phagocytic cells actively engulfing and digesting the erythrocytes; some of their phagosomes ("siderosome") contained iron-laden micelles sometimes arranged in a crystalline lattice. The synovial vessels were remarkable in two respects: first, there was evidence of endothelial breakdown; second, the basement membranes were strikingly multilayered.
mesh_terms: D000293:Adolescent; D001485:Basement Membrane / Q000648:ultrastructure; D005260:Female; D006801:Humans; D006965:Hyperplasia; D007718:Knee Injuries / Q000150:complications; D008833:Microcirculation / Q000473:pathology*; D008854:Microscopy, Electron; D009336:Necrosis; D013583:Synovial Membrane / Q000648:ultrastructure*; D013585:Synovitis / Q000473:pathology*; D013586:Synovitis, Pigmented Villonodular / Q000209:etiology / Q000473:pathology*