A pap smear is a way to examine cells collected from the cervix the main purpose it to detect cancer or abnormal cells that may lead to cancer. It can also detect infection and inflammation.
A pap smear is important because it can detect abnormalities that may lead to cancer of the cervix. These abnormalities can then be treated before cancer develops and most cancers can be prevented if women have pap smears regularly.
Cancer of the cervix is more likely to be treated successfully if it is detected early.
How is a pap smear done?
A pap smear is performed as part of a gynaecological exam. It can be done in a doctor's office, clinic or hospital. That patient lies on a table and places her feet in stirrups to position the pelvis for examination.
A speculum an instrument used to open the walls of the vaginal canal to see the interior will be inserted into the vagina and opened slightly.
A sample of cells from the outside and the canal of the cervix is taken by gently scraping the outside of the cervix with a wooden or plastic spatula and then inserting a small brush that looks like a pipe cleaner into the canal.
The cells are then placed on a glass slide and sprayed with a fixative or put into a bottle and then sent to a laboratory for testing.
There may be some discomfort similar to menstrual cramps and a feeling of pressure while the test is being done. A small amount of bleeding may occur after the test.
How to prepare for the test?
You should inform the doctor or nurse whether you have had an abnormal pap smear before, if you might be pregnant or if you are taking any medication or birth control pills.
Do not douche, using tampons, have sexual intercourse and bath for 24 hours before the test.
Do not schedule your pap smear while you are menstruating because blood cells from the endometrial cavity may obscure the accuracy of the test.
Who should have a pap smear and how often?
It is recommended that women have regular pap smears once a year beginning about three years after they begin having sexual intercourse but no later than 21 years old.
Once you have had three normal pap smears you should continue having a pap smear once every three years.
Women aged 65-70 who have had at least three normal pap smears and no abnormal tests in the last 10 years may decide after talking to her doctor to stop having pap smears.
Women who have had a hysterectomy do not need to have a pap smear unless the surgery was done as a treatment for pre-cancer or cancer.
How are the results of a pap test reported?
There are several possible results you can receive.
Samples that have no cell abnormalities are reported as negative or normal. This indicates that no changes have been found.
If a sample comes back abnormal there are three categories that describe why it is abnormal.
- ASCUS – atypical squamous cells of undetermined significance
- LGSIL – low-grade squamous intraepithelial lesions
- HGSIL – high-grade squamous cells
What do abnormal results mean?
Abnormal conditions do not always become cancerous and some conditions are more likely to lead to cancer than others.
There are several terms that might be used to describe abnormal results.
This is not cancer although it may develop into very early cancer of the cervix. The cells look abnormal under microscope but they do not invade nearby tissue.
There are four degrees of dysplasia: mild, moderate, sever and carcinoma in situ. This depends on how abnormal cells appear under microscope.
Carcinoma in situ means that cancer is present in the layer of cells on the surface of the cervix and has not spread to nearby tissues.
Squamous intraepithelial lesion (SIL)
Squamous describes thin flat cells that form the outer surface of the cervix and lesion refers to abnormal tissue.
An intraepithelial lesion means that the abnormal cells are present only in the layer of cells on the surface of the cervix.
SIL may be described as being low-grade (early changes in the size, shape and number cells) or high-grade (precancerous cells that look very different from normal cells).
Cervical intraepithelial neoplasia (CIN)
Neoplasia means an abnormal growth of cells. Intraepithelial refers to the layer of cells that form the surface of the cervix. CIN describes how much of the thickness of the linking of the cervix contains abnormal cells.
Atypical squamous cells are findings that are unclear and not a definite abnormality.
Cervical cancer occurs when abnormal cells spread deeper into the cervix or to other tissue organs.
What happens if my results are abnormal?
If results show abnormal you may need to repeat the test to determine whether follow up is needed.
In many cases cell changes go away without treatment. In some cases doctors may prescribe estrogen cream for women who have ASCUS.
If the results show a finding of ASCH, LSIL or HSIL the doctor may perform a coloposcopy using an instrument that looks like a microscope to examine the vagina and the cervix.
If coloposcopy shows abnormal tissue the doctor may perform endocervical curettage or biopsy. A biopsy is the removal of cells or tissue from the abnormal area for examination. And endocervical curettage involves scraping cells from inside the endocervical canal.
If testing shows abnormal cells that have a high chance of becoming cancer, further treatment will be needed. Without treatment the cells could turn into invasive cancer.
Treatment options include:
- LEEP (loop electrosurgical excursion procedure) is surgery that uses and electrical current which is passed through a thin wire loop to act as a knife
- Cryotherapy destroys abnormal tissue by freezing it
- Laser therapy uses a narrow bean of intense light to destroy or remove abnormal cells.
- Conization removes a cone-shaped piece of tissue using a knife or laser or LEEP
(Source: National Institute of Health)