title: Myopathy in a patient with systemic AA amyloidosis possibly induced by psoriasis vulgaris: An autopsy case.
abstract: BACKGROUND
  Amyloid myopathy is a rare manifestation of primary systemic amyloid light-chain (AL) amyloidosis, but it has not been reported to occur in secondary amyloid A (AA) amyloidosis.
  
  
  METHODS
  We describe a 46-year-old man with psoriasis vulgaris who presented with idiopathic upper and lower limb weakness and was eventually diagnosed with hypertrophic cardiomyopathy. Muscle biopsy findings were compatible with mild inflammatory myopathy. He died of cardiopulmonary arrest, and an autopsy was performed.
  
  
  RESULTS
  The autopsy revealed amyloid plaques immunopositive for AA (but not AL or transthyretin) in the perimysial, perivascular, and endomysial regions of the iliopsoas muscle. The final diagnosis was systemic AA amyloidosis with muscle amyloid angiopathy, possibly induced by psoriasis vulgaris.
  
  
  CONCLUSIONS
  This is an extremely rare autopsy case of myopathy in a patient with systemic AA amyloidosis. The reason for the unusually large amount of amyloid deposition in muscle blood vessel walls remains unclear.
authors.affiliation: Department of Neurology, Oita Prefectural Hospital, 476 Bunyo, Oita, 870-0855, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Tanabe
authors.affiliation: Department of Neurology, Oita Prefectural Hospital, 476 Bunyo, Oita, 870-0855, Japan.
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Maki
authors.affiliation: Department of Clinical Laboratory, Oita Prefectural Hospital, Oita, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Urabe
authors.affiliation: School of Health Sciences, Faculty of Medicine, Kagoshima University, Kagoshima, Japan.
authors.forename: Itsuro
authors.initials: I
authors.lastname: Higuchi
authors.affiliation: Diagnostic Unit for Amyloidosis, Department of Laboratory Medicine, Kumamoto University Hospital, Kumamoto, Japan.
authors.forename: Konen
authors.initials: K
authors.lastname: Obayashi
authors.affiliation: Department of Neurology, Oita Prefectural Hospital, 476 Bunyo, Oita, 870-0855, Japan.
authors.forename: Youichi
authors.initials: Y
authors.lastname: Hokezu
mesh_terms: D000686:Amyloidosis / Q000209:etiology* / Q000469:parasitology*; D001344:Autopsy; D006801:Humans; D000075363:Immunoglobulin Light-chain Amyloidosis; D008297:Male; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D009135:Muscular Diseases / Q000209:etiology* / Q000469:parasitology*; D011228:Prealbumin / Q000378:metabolism; D011565:Psoriasis / Q000150:complications*; D000685:Serum Amyloid A Protein / Q000378:metabolism
chemical_list: D011228:Prealbumin; D000685:Serum Amyloid A Protein
keywords: AA amyloidosis; hypertrophic cardiomyopathy; muscle amyloid angiopathy; psoriasis vulgaris; serum amyloid A