Bladder
Acquired nonneoplastic anomalies
Amyloidosis

Author: Alcides Chaux, M.D. (see Authors page)

Revised: 11 July 2018, last major update March 2011

Copyright: (c) 2003-2018, PathologyOutlines.com, Inc.

PubMed Search: Bladder amyloidosis
Cite this page: Chaux, A. Amyloidosis. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/bladderamyloidosis.html. Accessed September 25th, 2018.
Definition / general
  • Deposition of amyloid protein in urinary bladder
  • Almost always primary (amyloid tumor); rarely part of systemic disease
Sites
  • Preferentially affects posterior and posterolateral walls
Etiology
Systemic
  • Can be primary (AL type amyloid), secondary (AA type amyloid) or familial (ATTR type amyloid)
  • Systemic secondary bladder amyloidosis is associated with autoimmune disease and chronic infection
  • Familial cases are associated mostly with mutations in the transthyretin gene

Localized
Clinical features
Treatment
  • Transurethral resection and fulguration of amyloid tumor is usually curative, since not associated with myeloma (Am J Surg Pathol 1978;2:141); also controls bleeding
  • Partial cystectomy for large, mass forming lesions
Microscopic (histologic) description
  • Large masses of eosinophilic proteinaceous material with hemorrhage in lamina propria
  • Variable foreign body giant cell reaction to amyloid
  • May have associated atypical epithelium due to attenuation of urothelium
  • Rarely perivascular amyloid deposits, especially in systemic amyloidosis
  • Rare / no inflammatory cells
Microscopic (histologic) images

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Laryngeal amyloidosis

Positive stains
  • Congo red shows apple green birefringence when exposed to polarized light
  • Amyloid panel (kappa and lambda light chains, prealbumin, beta-2-microglobulin, SAA1)
  • Immunofluorescence with Thioflavin T
Electron microscopy description
  • Nonbranching, randomly distributed, rigid fibrils (8 - 10 nm) and associated ground substance
Differential diagnosis
  • Fibrosis: positive for trichrome stain, negative for Congo Red, no Thioflavin T immunofluorescence