Cystoscopy done, no tumors found, but took a urine cytology specimen to look for cancer cells. what percent of people have cancer with no tumors?

Terms are confusing: "Tumors" are "Growths" and appear as masses which by the way can be cancerous and non-cancerous, and :cancers" can be benign or malignant. The test for cancer cells is a lot more "SENSITIVE: than the search for tumors or masses. Hope this helps and Good Luck Dr Z

Depends: Obtaining a urine cytology is standard practice at time of cystoscopy. It can be helpful to determine if there is high grade cancer in the drainage system of kidneys. Also there is a form of high grade bladder cancer that is limited to the lining of the bladder. In these cases, there would be no visible tumor seen.