title: Warfarin-induced spondyloarthropathy with pseudotumor-like appearance. A case report.
abstract: METHODS
  This case report illustrates an unusual complication of chronic warfarin administration.
  
  
  OBJECTIVE
  The presurgical determination that the destructive process at L1-L2 was not infection or neoplasm involved the recognition that there was instability at this level resulting from chronic stress fractures.
  
  
  BACKGROUND
  Periosteal or osseous hemorrhagic masses (pseudotumors) have been well described in patients with hemophilia. To the authors' knowledge, this is the first reported case of this well-known phenomenon occurring in the axial skeleton as a consequence of warfarin administration.
  
  
  METHODS
  Serial radiographic studies of the lumbar spine were available showing a progressive destructive lesion at L1-L2 and coinciding with the initiation of warfarin anticoagulation after aortic valve replacement.
  
  
  RESULTS
  The destructive mass was demonstrated surgically to represent a large partially solidified chronic hematoma.
  
  
  CONCLUSIONS
  Patients with stress fractures of the posterior arch and subsequent instability may be subject to development of such a spondyloarthropathy. Recognition of this unusual potential complication of warfarin therapy would prevent an incorrect diagnosis of tumor or infection. Early recognition of its occurrence could lead to early spinal stabilization.
authors.affiliation: Department of Radiology, St. Louis University Health Sciences Center, Missouri, USA.
authors.forename: E E
authors.initials: EE
authors.lastname: Awwad
authors.forename: R J
authors.initials: RJ
authors.lastname: Bernardi
authors.forename: M
authors.initials: M
authors.lastname: Sundaram
mesh_terms: D000368:Aged; D015775:Fractures, Stress / Q000150:complications*; D006406:Hematoma / Q000139:chemically induced; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries*; D008297:Male; D011859:Radiography; D013122:Spinal Diseases / Q000000981:diagnostic imaging / Q000209:etiology*; D013167:Spondylitis, Ankylosing / Q000139:chemically induced* / Q000000981:diagnostic imaging; D014859:Warfarin / Q000009:adverse effects*
chemical_list: D014859:Warfarin