RESUMEN
Primary amyloidosis results from the deposition of amyloid protein fibrils in the extracellular space and rarely involves the urinary bladder. We present a 41-year-old man who was diagnosed with primary amyloidosis of the urinary bladder and underwent two sessions of transurethral resection of the bladder mass 4 years prior. Recently, the patient was admitted through the emergency with painless frank haematuria. Computed tomography of the abdomen and pelvis revealed a bladder mass that was larger than the previously reported mass. A repeat cystoscopy and resection of the mass was performed. Histopathological examination of the resected tissue revealed primary amyloidosis of the urinary bladder. A comprehensive examination was performed to exclude systemic amyloidosis.