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Myopathy in a patient with systemic AA amyloidosis possibly induced by psoriasis vulgaris: An autopsy case

Hajime Tanabe1, Yoshimitsu Maki1, Shogo Urabe2

  • 1Department of Neurology, Oita Prefectural Hospital, 476 Bunyo, Oita, 870-0855, Japan.

Muscle & Nerve
|July 17, 2015
PubMed
Abstract

Insights

This autopsy case reveals amyloid A (AA) amyloidosis causing myopathy in a patient with psoriasis. AA amyloid deposition was found in muscles, a rare occurrence previously unreported in secondary amyloidosis.

Area of Science:

  • Neurology
  • Pathology
  • Rheumatology

Background:

  • Amyloid myopathy is a rare manifestation of primary systemic amyloid light-chain (AL) amyloidosis.
  • It has not been previously reported in secondary amyloid A (AA) amyloidosis.

Observation:

  • A 46-year-old man with psoriasis vulgaris presented with progressive limb weakness and hypertrophic cardiomyopathy.
  • Muscle biopsy showed mild inflammatory myopathy.
  • The patient died of cardiopulmonary arrest.

Findings:

  • Autopsy revealed amyloid plaques immunopositive for AA amyloid in the muscle.
  • These plaques were located in the perimysial, perivascular, and endomysial regions.
  • The diagnosis was systemic AA amyloidosis with muscle amyloid angiopathy, potentially linked to psoriasis vulgaris.

Implications:

  • This is an extremely rare autopsy case of myopathy in systemic AA amyloidosis.
  • The significant amyloid deposition in muscle blood vessel walls is unusual and warrants further investigation.
  • Highlights a potential, previously unreported, complication of AA amyloidosis.
Keywords:
AA amyloidosishypertrophic cardiomyopathymuscle amyloid angiopathypsoriasis vulgarisserum amyloid A

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