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Primary localized amyloidosis of the urinary bladder: a case series of 31 patients.

OBJECTIVE
To evaluate the presentation and prognosis of primary localized amyloidosis of the urinary bladder.


PATIENTS AND METHODS
The medical records of 31 patients with primary localized amyloidosis of the urinary bladder were reviewed. Immunohistochemical amyloid typing was performed on bladder biopsy specimens from 27 patients.


RESULTS
The median age of the 22 men and 9 women was 55 years. Twenty-four patients (77%) presented with gross hematuria (associated with irritative urinary tract symptoms in 6 patients), and 7 (23%) had only irritative lower urinary tract symptoms. Multiple bladder areas were involved in 20 patients (65%), a single area was involved in 8 (26%), and diffuse involvement was present in 3 (10%). Twenty-four patients had immunoglobulin light chain, and 3 had transthyretin-related amyloid. Local recurrences were common. None of the patients developed systemic amyloidosis.


CONCLUSION
Primary localized amyloidosis of the urinary bladder can be easily confused with a neoplasm. Immunohistochemical amyloid typing is important. Transthyretin-related amyloid of the bladder requires no further work-up. Repeated work-ups for systemic amyloidosis are unnecessary for patients with light chain-related amyloidosis of the urinary bladder. Early eradication with fulguration or laser therapy is indicated. Cystoscopic follow-up is necessary.