What is a pap smear?

Your cervix is the lower, narrow end of your uterus. The cells in the tissue covering the cervix grow all the time. The cells at the bottom layer of tissue move to the surface during this process. Some cells can become abnormal during this growth process, usually as a result of exposure to human papilloma virus. If the abnormal cells are allowed to grow unchecked, they could lead to cancer.

The Pap test looks at a sample of cells taken from your cervix. It will help your doctor to identify abnormal cells. A Pap test is only used to detect abnormal cells on your cervix; it cannot detect precancerous or cancerous cells in other parts of your body.

What do my test results mean?

There are several possible results from your Pap smear:

• normal (negative): no abnormal cells were seen
• atypical squamous cells of unidentified significance (ASC-US): some abnormal cells were seen. These may be from an infection, irritation, or may be precancerous.
• low grade squamous intraepithelial lesion (LGSIL): early, mild cell changes were seen
• high grade squamous intraepithelial lesion (HGSIL): moderate or severe cell changes were seen
• carcinoma in situ (CIS): severe cell changes- this is the most likely to progress to cancer
• atypical glandular cells: indicates increased risk for precancer or cancer of female reproductive organs
• cancer: abnormal cells have spread deeper into the cervix or to other tissues

What is the role of human papilloma virus (HPV) in abnormal Pap results?

Human papillomavirus (HPV) is a virus that is spread by direct skin-to-skin contact, including sexual intercourse, oral sex, anal sex, or any other contact involving the genital area (eg, hand to genital contact). HPV is a very common infection with over 100 different types. Of these, 15 are known to cause most cases of cervical cancer. Researchers have labeled the HPV types as being high or low risk for causing cervical cancer. The low risk strains of HPV can cause genital warts. There is no treatment, but there is a vaccine available now. Most people who are infected with HPV have no signs or symptoms and clear the infection within two years, often without treatment. In 10 to 20 percent of patients, however, the infection persists. In this situation, there is a higher likelihood of developing cervical cell abnormalities or cancer. However, it usually takes several years for HPV infection to cause cervical cancer. Thus, regular pap smears are important in detecting abnormal cervical cells early, before cancer develops.

In some instances, your doctor may order an HPV test to help clarify the Pap results. Women who have abnormal Pap results and are positive for certain types of HPV will need further testing.

I have an abnormal Pap smear. What now?

The key to treating cervical changes is to catch them early. Depending on your results, you may only need a repeat Pap test because many cell changes go away on their own. Further testing methods, such as colposcopy and biopsy, can help your doctor know the reason for the abnormal results. A colposcope is similar to a microscope and helps your doctor look more closely at your cervix. A speculum is inserted into your vagina. The colposcope remains outside the vagina, but the doctor will look through it to see the cervical cells up close. Vinegar is applied to the cervix to make the abnormal cells easier to see. This sometimes causes mild burning. If abnormal cells are seen, your doctor will probably perform a biopsy. A small sample of tissue will be pinched from your cervix and sent to a lab for further study. You may have mild cramping and light bleeding after the procedure.

If your results show that your cells are at higher risk for progressing to cancer, you may need to have surgery. This would be done at the hospital under anesthesia and you would normally go home the same day. A loop electrosurgical excision procedure (LEEP), is often performed for women with HGSIL. A thin wire loop carrying an electric current is used to remove abnormal areas of the cervix. A cone biopsy is done to obtain a cone-shaped wedge of the cervix. The tissue sample is sent to the lab for further testing. After either procedure, you should expect cramping and light bleeding while your cervix heals. After cervical surgery, you may also be at increased risk for preterm birth or infertility.

References:

Abnormal Pap Test Results patient education pamphlet. American College of Obstetricians and Gynecologists 2004.

McGovern, Barbara H. Patient information: Human papillomavirus (HPV) vaccine. www.uptodate.com 2009.