Primary Localized Amyloidosis of Urinary Bladder: A Case Report and Review of Literature

Amyloidosis is a disorder of protein metabolism characterized by extracellular deposition of abnormal protein fibrils. It may either be localized to any organ or systematically distributed throughout the body. The biochemical nature of proteins varies but the physical and tinctorial properties are shared by all the amyloidogenic proteins. In the West, it is mainly composed of amyloid light (AL) type immunoglobulin (Ig) light chains. Amyloidosis of the genitourinary tract is rare except for the kidney and isolated primary amyloidosis of the urinary bladder is even rarer. It mainly presents as intermittent painless gross hematuria. It mimics transitional cell carcinoma on imaging and endoscopic examination. We herein present a case of fifty six-years-old male with history of painless hematuria for three months. Cystoscopy revealed a 1 cm hyperemic area on the posterior wall of urinary bladder. The biopsy showed features of amyloidosis and amyloid A (AA) immunostaining was negative. Extensive workup was done to exclude other sites of involvement and a final diagnosis of primary localized amyloidosis of the urinary bladder was made. The patient is on regular follow-up.