HPV and Anal PAP Testing
(Anal Papanicolaou Smear)
The anus is the opening at the lower end of the large intestine, below the rectum. The anus is
formed partly from outer skin layers of the body and partly from intestinal tissues. Two ring-like
muscles, called sphincter muscles, control the passage of stool from the body. The anal canal,
the part of the anus between the rectum and the anal opening, is about 1 ½ to 2 inches long.
HPV and Anal Cancer
Human Papillomavirus (HPV) is a very common virus that men and women can get during
sexual contact. More than half of people who are sexually active get HPV at some time in their
lives. They often don’t know it because they don’t have symptoms or other health problems.
Our immune system (the system in our bodies that helps fight infection and disease) can often
clear it out, but certain types of HPV are hard to fight. There are more than 100 types of HPV.
Some types of HPV cause common warts of the hands or feet, but these are not usually spread by
sexual activity. Other types of HPV may cause warts or changes in the cells of the skin, mouth,
or genitals (penis, vagina, or anus). Still other types of HPV can lead to anal cancer or cancer of
the cervix in women if they are not caught early. The types of HPV that cause genital warts are
not the same as the types of HPV that cause cancer.
HPV is the main cause of anal cancer. Risk factors for anal cancer include HIV infection, having
anal sex or multiple sex partners, and smoking. People who have weak immune systems, such as
those who have had organ transplants or need to take drugs to suppress their immune systems,
also have a higher risk of anal cancer.
In recent years the number of people getting anal cancer, especially men who have sex with men,
has been on the rise. People with HIV often have a harder time fighting HPV, so it is important
that men, as well as women with HIV, get tested for HPV infection. An anal pap test may be
helpful in finding changes in cells so that anal cancer could be prevented or caught early.
What is an anal pap test?
An anal pap test is a screening test that can be done on men and women. It is a test that looks for
changes in the cells of the anus that could lead to anal cancer (very much like pap smears of the
cervix in women). The anal pap test does not test for colon or rectal cancer.
How is the anal pap test done?
The anal pap test will take less than 5 minutes. In most cases, it will cause little or no
During this test, you may be asked to lie on your side on an exam table, or may be asked to bend
forward over an exam table. Your provider will insert a swab, which looks like a long, thin Q-
tip, about 1 ½ - 2 inches into your anus, and will collect a sample of cells. The sample is then
sent to the lab, where the cells are looked at under a microscope to see if there are any changes.
You will receive the results of the test in 1-2 weeks.
What do the results mean?
ξ Negative. The cells are normal. Your provider will repeat the anal pap in one year.
ξ Unsatisfactory. The sample of cells was not adequate for evaluation. Your provider
will repeat the anal pap in 3-6 months.
ξ ASCUS (Atypical Squamous Cells of Undetermined Significance). There are some
unusual cells, but it is unclear what this means. This is a mild abnormality. THIS
DOES NOT MEAN YOU HAVE CANCER.
ξ ASC-H (Atypical Squamous Cells, cannot exclude a High Grade Anal Squamous
Intraepithelial Lesion (HSIL). This could be a mild or severe abnormality. THIS
DOES NOT MEAN YOU HAVE CANCER.
ξ LSIL (Low Grade Anal Squamous Intraepithelial Lesion). This is a mild abnormality.
THIS DOES NOT MEAN YOU HAVE CANCER.
ξ HSIL (High Grade Anal Squamous Intraepithelial Lesion). This is a more severe
abnormality. THIS DOES NOT MEAN YOU HAVE CANCER.
ξ Squamous Carcinoma. This is a rare result that means the cells show major changes
that might be cancer. In this case, a specialist will take tiny samples of tissue (do a
biopsy). These samples are sent to a lab to be looked at under a microscope in order to
see changes in the cells that might be cancer.
What if my results are abnormal?
If you have an abnormal pap test, your provider will tell you what follow-up tests will be needed
and will arrange to have them done at a later date.
Centers for Disease Control. (November 24, 2009). Genital HPV Infection – CDC Fact Sheet. Retrieved June 9,
2010 from http://www.cdc.gov/std/hpv/stdfact-hpv.htm.
Palefsky, J.M., Holly, E.A., Hogeboom, C.J., Berry, J.M., Jay, N., Darragh, T.M. (15April1997). Anal cytology as a
Screening Tool for Anal Squamous Intraepithelial Lesions. Journal of Acquired Immunodeficiency Syndromes and
Human Retrovirology, volume 14, pages 415-422.
Your health care team may have given you this information as part of your care. If so, please use it and call if you
have any questions. If this information was not given to you as part of your care, please check with your doctor. This
is not medical advice. This is not to be used for diagnosis or treatment of any medical condition. Because each
person’s health needs are different, you should talk with your doctor or others on your health care team when using
this information. If you have an emergency, please call 911. Copyright ©12/2016. University of Wisconsin Hospitals
and Clinics Authority. All rights reserved. Produced by the Department of Nursing. HF#7056.