Primary localized AA type amyloidosis of urinary bladder: case report of rare cause of episodic painless hematuria.

A 45-year-old diabetic man presented with an episodic history of painless gross hematuria. He had had no previous urinary symptoms or any other medical problems. His physical examination, urine cytology, and computed tomography scan findings were normal. Cystoscopy demonstrated two nodular masses in the urinary bladder with a hemorrhagic mucosal surface. Biopsies revealed amyloidosis, and immunohistochemical staining of the specimens defined the process as amyloid AA (mostly seen in secondary amyloidosis). The workup for systemic conditions associated with amyloid AA was negative. This represents an unusual case of primary localized AA-type amyloidosis of the bladder.