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.