Home   Chapter Home   Jobs   Conferences   Fellowships   Books

Advertisement

Bladder

Acquired non-neoplastic anomalies

Amyloidosis

Reviewers: Alcides Chaux, M.D., Johns Hopkins University School of Medicine (see Reviewers page)
Revised: 26 March 2011, last major update March 2011
Copyright: (c) 2003-2011, PathologyOutlines.com, Inc.

Definition
=========================================================================

● Deposition of amyloid protein in urinary bladder
● Almost always primary (amyloid tumor); rarely part of systemic disease

Epidemiology
=========================================================================

● Very rare (<200 cases published up to date)
● Usually older patients (>50 years old)

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
● Unknown etiology
● Mostly AL-type amyloid (immunoglobulin light chains, Urology 2006;67:904)

Clinical features
=========================================================================

● Patients present with gross, painless hematuria (Mayo Clin Proc 2000 75:1264)
● May clinically resemble bladder cancer (Indian J Pathol Microbiol 2008;51:415)
● Urinary dysfunction found in 50% with familial amyloidotic polyneuropathy (Neurourol Urodyn 2009;28:26)
● Primary amyloidosis has a high rate of local recurrence
● Prognosis of secondary amyloidosis depends on primary cause

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

Gross
=========================================================================

● Mucosa erythema in diffuse amyloidosis, sometimes with petechiae and focal necrosis
● Nodular mucosal lesions resembling carcinoma in localized cases

Gross images
=========================================================================

Amyloidosis of urinary bladder (Courtesy of Dr. George M. Farrow, Rochester, Minnesota)

Micro 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

Micro images
=========================================================================

   
Eosinophilic proteinaceous material in lamina propria


Amyloid in the urinary bladder, in contrast to other sites, usually occurs as globular masses of amorphous acidophilic material

Subepicardial deposition of amyloid (Congo red stain with polarizing microscopy)


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
=========================================================================

● Non-branching, 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

End of Bladder > Acquired non-neoplastic anomalies > Amyloidosis

This information is intended for physicians and related personnel, who understand that medical information is often imperfect, and must be interpreted in the context of a patient's clinical data using reasonable medical judgment. This website should not be used as a substitute for the advice of a licensed physician.

All information on this website is protected by copyright of PathologyOutlines.com, Inc. Information from third parties may also be protected by copyright. Please contact us at copyrightPathOut@gmail.com with any questions (click here for other contact information).