A 68-year-old man presents to the emergency department complaining of blood in his urine as well as small blood clots for 3 days. He denies dysuria, nocturia, urinary frequency or hesitancy, or a decreased urinary stream. He denies any fevers, chills, or weight loss. He has had similar episodes of visible blood in his urine in the last several months and has been treated twice with antibiotics for a possible urinary tract infection without improvement. He has a history of hypertension for which he takes a beta-blocker; otherwise he has had no surgeries and takes no other medications. He denies any family history of malignancy or renal disease. He denies any history of trauma and does not vigorously exercise. He has a 40-pack-year history of smoking and worked as a painter. On physical exam, he is afebrile with normal vital signs. His abdomen is soft, without any palpable masses. His genitourinary exam reveals a normal circumcised phallus without lesions and normal bilateral descended testicles. On digital rectal exam, his prostate is small without any nodularity, induration, or tenderness. On laboratory exam, his hematocrit is 42%, creatinine is 1.0 mg/dL, international normalized ratio (INR) and partial thromboplastin time (PTT) are normal, and prostate-specific antigen (PSA) is within normal limits. His urinalysis shows a large number of red cells, no white cells, no casts, and no bacteria.