Urine cytology is useful for patients on surveillance after treatment of transitional cell carcinoma of the urinary tract (e.g. urethra, bladder, ureters, renal pelvis). This is when the urine is sent to the laboratory to be looked under a microscope to detect cancer cells.
High-grade transitional cell carcinoma (TCC) and carcinoma-in-situ of the urinary tract is known to shed these cancer/carcinoma cells into the urine and these abnormal cells will be picked up when the urine sample is sent for cytology.
However, a negative urine cytology result does not rule out cancer of the urinary tract completely as low-grade TCC do not shed cells into the urine.
When a urinary cytology is positive and the cause of it is not evident, this would necessitate further work-up. This would include endoscopic procedures (i.e. scopes) to look at the lining of the urinary tract, referred to as the urothelium. Scopes can be performed from the urethra all the way up into the bladder and into both ureters and both renal pelvis to look for any suspicious-looking tumours.
