A 62-year-old man presents to the clinic with painless gross…
A 62-year-old man presents to the clinic with painless gross hematuria for the past two weeks. He has a 40-pack-year smoking history and poorly controlled hypertension. Physical exam reveals a left-sided varicocele that does not decompress when he lies supine. UA confirms hematuria without infection or red blood cell casts. What diagnostic study is considered the gold standard for the suspected diagnosis?