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.