A Pap test, or Papanicolaou test, is a procedure that removes a small sample of cells from the cervix. Cells are looked at under a microscope to see if they are normal or abnormal.
Why a Pap test is done
A Pap test is mainly used to:
- screen for and help diagnose precancerous conditions of the cervix and cervical cancer
- help diagnose precancerous conditions of the vagina and vaginal cancer
- diagnose infection and inflammationinflammationThe body’s protective response to injury or infection that includes redness, swelling, pain and warmth of the affected area. in the lower female reproductive tract
Pap tests are also done to follow up after an abnormal Pap test or to monitor precancerous conditions. They are used to check for abnormal cell changes or to see if cancer comes back (recurs) after treatment.
Find out more about cervical cancer screening.
How to prepare for a Pap test
Try to avoid having a Pap test during menstruation, or when you have your period. For best results, the test should be done in the middle of your cycle, 10–20 days after the first day of your menstrual period. Talk to your doctor or nurse if your appointment falls during your period. If your period is light, it may be possible to do the Pap test.
Avoid having sexual intercourse for 24 hours before the test. Do not use a vaginal douche, vaginal medicines, tampons or contraceptive (spermicidal) creams, foams or gels (except as directed by your doctor) for 48 hours before the test. These products can wash away or hide abnormal cells.
Avoid having the test during treatment for any cervical or vaginal infection. Wait 2 weeks after treatment has ended.
Try to empty your bladder right before the Pap test. A full bladder may make having the test uncomfortable.
How a Pap test is done
A Pap test may be done as part of a checkup or during a pelvic, or gynecologic, exam. A pelvic exam is done to make sure the pelvic organs are normal and to check for infections. Find out more about pelvic exam.
A Pap test is usually done in a doctor’s or nurse’s office or in a clinic. It only takes a few minutes to do a Pap test. There may be some discomfort, pressure or cramping during the procedure, but it is not usually painful.
To do a Pap test, the doctor or nurse gently places a speculum into the vagina. A speculum is a clear plastic or metal device. It separates the walls of the vagina so the doctor can see the upper part of the vagina and cervix.
The doctor or nurse uses a small stick, or spatula, to gently scrape the surface of the cervix to pick up cells. In some cases, a special brush (called a cytobrush or cytobroom) is used to collect cells from the inner part of the cervix, which leads into the uterus. Samples of tissues from the vagina can also be taken during a Pap test.
After collecting the cells, the doctor or nurse smears them onto a glass slide or places them in a container filled with a special liquid (called a liquid-based Pap test). The liquid containing the sample of cells may also be used to test for HPV. If the cells are smeared onto a glass slide, they are treated with a special solution called a fixative. The fixative preserves the appearance of the cells. The sample is sent to a lab to be processed so it can then be examined under a microscope.
You may have some light vaginal bleeding for 1–2 days after a Pap test. It may take 2–8 weeks for a Pap test result to come back from the lab.
What the results mean
Sometimes the sample is not good enough to give a clear result. This can happen if there is too much blood, not enough cells or the fixative did not preserve the cells well. Your doctor or nurse will let you know if the test has to be repeated.
When there is a good sample, labs in Canada use the Bethesda system to report Pap test results. In this system, a Pap test result may be described as normal (also called negative) or abnormal.
A normal, or negative, result means that there were enough cells in the sample and no abnormal or cancerous cells were found. A normal Pap test report may also note if non-cancerous, or benign, conditions are present, such as common infections or inflammation.
Abnormal cells in the cervix or vagina may be classified based on how different they look from normal cells. How abnormal they are may be described as mild to severe. Abnormal cells in the cervix are also described using the Bethesda reporting system, which gives information about the type of cell change found.
Abnormal results don’t necessarily mean there is a precancerous condition or cancer. Some abnormal cells return to normal on their own. Other abnormal cells or precancerous changes in the cervix or vagina may develop into cancer over time if they aren’t treated. This includes:
- squamous cell carcinoma (SCC)
- other types of cancer
What happens if the result is abnormal
If the result of a Pap test is abnormal, your doctor will decide if you need to have follow-up tests, treatment or both. Some changes or abnormalities may need to be treated, depending on how severe they are.
Follow-up options include another Pap test or a colposcopy (a procedure that uses a lighted magnifying instrument, called a colposcope, to examine the vulva, vagina and cervix).
Risks with a Pap test
Screening tests, including the Pap test, have a risk of giving misleading results.
A false-negative result means that the test doesn’t find cancer or abnormal cells even though they are present. This may occur if the sample doesn’t have enough tissue or cells. It can also happen when abnormal cells in the sample are missed.
A false-positive result means that the test shows abnormal cells even though they are not present. This means that something looked like a precancerous condition, but it actually isn’t. A false-positive result may lead to unnecessary follow-up tests, procedures and anxiety.
Research at the Canadian Centre for Applied Research in Cancer Control led to a new standard in leukemia testing.
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