title: Synovial fluid crystals derived from erythrocyte degradation products.
abstract: We report 5 patients with bloody effusions containing crystals not previously reported to occur in synovial fluid. In one patient, rectangular hemoglobin-like crystals were found inside red cells previously observed elsewhere. In the other 4 cases, golden brown rhomboid crystals with positive elongation appeared to be hematoidin, a degradation production of hemoglobin, which has been found in nonarticular areas of old hemorrhage. In one patient, hematoidin crystals were identified lying in macrophage vacuoles. Both types of crystals are potential sources of confusion with known pathogenic crystals.
authors.affiliation: Veterans Administration Medical Center, Philadelphia, PA 19104.
authors.forename: G A
authors.initials: GA
authors.lastname: Tate
authors.forename: H R
authors.initials: HR
authors.lastname: Schumacher
authors.forename: A J
authors.initials: AJ
authors.lastname: Reginato
authors.forename: S B
authors.initials: SB
authors.lastname: Algeo
authors.forename: G M
authors.initials: GM
authors.lastname: Gratwick
authors.forename: W T
authors.initials: WT
authors.lastname: Di Battista
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001663:Bilirubin / Q000032:analysis*; D016923:Cell Death / Q000502:physiology; D003460:Crystallization; D004912:Erythrocytes / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D005260:Female; D006454:Hemoglobins / Q000032:analysis / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D013582:Synovial Fluid / Q000737:chemistry*
chemical_list: D006454:Hemoglobins; D001663:Bilirubin