Urine cytology is a microscopic examination of cells found in the urine. It is a diagnostic test that may be ordered if a doctor suspects that a patient has a cancerous growth in the urinary tract or if a patient appears to have a urinary inflammation or infection. The test is painless for patients and it is a very cost effective tool for diagnosis and follow up on medical treatments. Many labs have the capacity to handle urine cytology tests and can ship samples if their technicians are not able to examine them.
When people urinate, epithelial cells from inside the urinary tract are shed in the urine. In healthy individuals, there will be relatively few cells and they should all have a normal appearance. In people with urinary tract diseases, more cells will be present and some of the cells may have abnormalities. By examining the cells found in a urine sample, a lab technician can identify signs of disease.
Samples for urine cytology are usually collected by asking the patient for a clean catch sample, where the patient cleans the genitals, starts urinating to clear the urethra of any contaminants, and then finishes urinating in a sterile container. In some cases, a catheter may be used to collect urine if a sample cannot be collected by other means. It is important to avoid using the first urination of the day for urine cytology because it contains cells that have been carried overnight in the bladder and these cells may be degraded, leading to a false positive.
Urine cytology can be requested if a patient has bloody urine or other symptoms of infection or neoplasm, such as difficulty urinating, painful urination, strong smelling urine, discolored urine, and frequent urges to urinate. A doctor can also use this diagnostic test as a follow up for a patient who has received treatment for a urinary tract condition. If the treatment was successful, the urine cytology results should be clear, showing no abnormal cells in the urine.
The precision of this test varies. A lab technician can identify cellular changes but may not be able to determine what is causing the changes. If the cells are cancerous, additional testing will be needed to pinpoint the site of the cancer and stage it. If the urine shows signs of inflammation or infection, testing can be used to find the root cause so that it can be treated. Positive urine cytology results are usually verified with additional testing before treatment recommendations are made.