Urine cytology involves looking under a microscope for abnormal cells in order to detect urinary tract (bladder, kidney, ureter and urethra) cancers. This analysis is often ordered after red blood cells are found in a routine urine test. Cytology is also used in a preventive manner for certain workers exposed to toxic substances or to monitor bladder cancer treatment. Urinary cytology results are always confirmed by a pathologist.
A cytology result can be considered negative if it contains no malignant (cancer) cells or atypical cells.
The presence of malignant cells is suggestive of bladder cancer and is usually followed by other confirmation analyses (cystoscopy, biopsy, ultrasound, etc.). Atypical cells are suspicious cells, which are neither normal nor clearly malignant. Degenerated cells are more difficult to identify and can be caused, for example, by poor specimen storage conditions or by the aging of cells in the bladder before sample collection.
Urinary cytology is not very sensitive and is often repeated three times to increase the chances of detecting abnormal cells.