What Is Cytology?
Cytology is the examination of cells from the body under a microscope. In a cytology exam of urine, cells collected from urine are sent to a laboratory and examined to see how they look and function. The test is commonly used to check for infection, inflammatory disease of the urinary tract, cancer, or precancerous conditions.
It is important to note that if cancer is not identified through this test, it does not necessarily mean you are cancer-free. Urine cytology is better at finding larger and more aggressive cancers than small, slow-growing cancers.
This procedure is different from a biopsy in that individual cells are being examined, instead of pieces of tissue containing many cell clusters. The cells for urine cytology are easier to obtain than tissue, causing less discomfort and less risk to the patient. Abnormal results from the urine cytology are sometimes followed-up with a biopsy to clarify the diagnosis.
Why the Procedure Is Performed
Your doctor may order a cytology exam of your urine if you have any of these symptoms:
- blood in your urine
- burning during urination
- pain during urination
The test is also used to monitor patients who have had urinary tract infections or cancer, those who are at high risk for bladder cancer, and to detect a variety of viral diseases.
How the Cells Are Obtained
There are two ways to obtain the cells needed for a cytology exam. Your doctor can collect a sample during a cystoscopy, which is an examination of the inside of the bladder, or you can provide a clean catch urine sample.
A cystoscopy is performed using a cystoscope (a thin tube with a small camera on the end). The procedure takes between 5 and 20 minutes.
Because the urine from your first morning urination remains in your bladder for many hours (through the night), the cells may degrade and not be useful for urine cytology. However, this doesn’t mean you should urinate right before the test. In fact, you may be asked to hold urine in your bladder for a few hours prior to a cystoscopy. Be sure to ask your doctor for specific instructions before the test.
For a cystoscopy, a healthcare professional will cleanse the skin around your urethra (tube coming out from the bladder) and use a topical gel to numb the area. The cystoscope will then be inserted into your urethra and up into your bladder. You may feel some pressure and an urge to urinate. Urine will be drained into a sterile container and the catheter removed.
The procedure carries a small risk of infection. The urine sample will be sent to a laboratory for analysis and a report will be sent to your doctor.
Clean Catch Urine Sample
A clean catch urine sample is easy, noninvasive, and carries no risk. Otherwise known as a midstream urine sample, this procedure can be carried out in a doctor’s office or in the comfort of your own home.
Your doctor’s office will provide a special kit to collect the sample. Be sure to ask your doctor for specific instructions regarding the proper way to get the sample and where to bring it when you are finished. Failure to follow instructions may provide a poor result, and you may have to repeat the test.
You will be given special cleansing cloths and instructed on how to clean the skin around your urethra prior to the test. You will need to urinate a small amount into the toilet, and then stop the flow of urine. Then you will urinate into the sterile container until reaching the desired level. You may then finish urinating into the toilet.
In some cases, your doctor may want you to provide urine samples over the course of several days. The urine sample will be sent to a laboratory for analysis and a report will be sent to your doctor.
What Happens in the Laboratory
Your urine sample will be sent to a laboratory so a pathologist can analyze the cells under a microscope to see if there are any abnormalities. The cells may also be placed in a culture dish to see if bacteria or other organisms are growing.
The pathologist will send the results of your urine cytology test to your doctor, who will report the results to you. Ask your doctor how long you can expect to wait for your results.
What the Test Results Mean
Different laboratories use different language in their reports. Your doctor will be able to explain what your results mean for you. These are some common terms that may be used to describe your results:
If your urine cells appear normal and are free of bacteria and yeast, this is considered a normal result. Most labs will call this a “negative” result.
The lab may label your specimen “unsatisfactory” if there were not enough usable cells in the sample. In this case, you will have to repeat the procedure and provide a new sample.
Atypical or Suspicious
These terms are used when cells do not appear normal, but it cannot be confirmed that they are cancerous or precancerous.
If bacteria or yeast are present in the culture, you probably have a bladder or urinary tract infection, which are usually treated with antibiotics.
Abnormal-appearing cells in your urine may also indicate inflammation in the urinary tract or cancer of the bladder, kidney, ureter, or urethra. However, an abnormal result for a cytology exam of urine cannot diagnose these diseases. Additional tests are usually necessary to confirm the diagnosis.