The Pap test
checks for changes in the cervix that may become cancer. If a Pap test
shows these changes, the result is called abnormal. In women who have
regular Pap tests, abnormal changes are almost always caught early. An
abnormal Pap test result may mean that further testing and follow-up are
This pamphlet explains
If you have an abnormal Pap test result, talk to
your doctor about what the result means and the recommended next steps.
The cervix is the opening of the
uterus at the top of the vagina. It is covered by a thin layer of
tissue. This tissue is made up of cells. As these cells develop, the
cells at the bottom layer slowly move to the surface of the cervix.
During this process, some cells may become abnormal or damaged. Damaged
cells grow differently. In some cases, these cells need to be removed to
These abnormal cells show early
precancer changes called dysplasia or cervical
intraepithelial neoplasia (CIN). Dysplasia and CIN are
graded as mild, moderate, or severe. Mild dysplasia (CIN 1) usually goes
away on its own. Moderate (CIN 2) and severe (CIN 3) dysplasia indicate
more serious changes.
The Pap test, also called a Pap
smear or cervical cytology screening, checks for abnormal changes in the
cells of the cervix and allows early treatment so that they do not
become cancer. Regular use of the Pap test has greatly reduced the
number of cases of cervical cancer in the United States.
HPV and Abnormal Pap Test
The main cause of abnormal Pap test results is infection with human
papillomavirus (HPV). There are many types of HPV. Some
types have been linked to cancer of the cervix, vulva, and vagina. Other
types have been linked to genital warts.
HPV infection is very common,
especially in women younger than 20 years. It is passed from
person to person through sexual contact. Usually, a woman’s immune
system clears the virus quickly, and the infection goes
away by itself. But in some women, HPV does not go away quickly. A small
number of these women will go on to develop CIN. The longer HPV is
present and the older the woman, the greater the risk she will develop
CIN. Smoking doubles the risk of CIN 3 when HPV is present. However, it
usually takes years for precancer changes in the cervix to cause
Pap Test Results: The
If you have an abnormal Pap test
result, some of the terms used can be confusing. Most labs use the
“Bethesda System” to describe Pap test results. This system uses the
term squamous intraepithelial lesion (SIL) to
describe precancer changes. “Squamous” refers to the type of cells that
make up the tissue that covers the cervix. With this system, your
results will be placed in one of several groups:
Cervical changes may be called a squamous intraepithelial lesion (SIL),
cervical intraepithelial neoplasia (CIN), or dysplasia. SIL is used to
describe Pap test results. CIN and dysplasia are used to describe the
actual changes in cervical cells.
Carcinoma in situ
If you are told that you have an
abnormal Pap test result, you may need further testing. The follow-up
that you receive after an abnormal Pap test result depends on your age
and the grade of dysplasia (see Table
1). Sometimes, there is more than one option for further testing.
You and your health care provider will discuss each option and decide
which is best for you.
Repeat Pap Test
For some women, one further
testing option is to repeat the Pap test a few months later. This may
give time for the changes to go away on their own. For women 21 years
and older with ASC–US, the test is given every 6 months until she has
two normal results. She then can return to the routine Pap test
schedule. For women 20 years and younger with ASC–US or LSIL, the Pap
test is repeated in 1 year.
Another option for some women is
an HPV test. This test detects the presence of cancer-causing types of
HPV in cervical cells. The cells used for the initial Pap test often can
be tested, so a woman does not need to return to the office for another
Colposcopy, Biopsy, and
Colposcopy lets your doctor look at the cervix
in more detail through a magnifying device. It can detect problems of
the cervix that cannot be seen with the eye alone. If an area of
abnormal cells is seen, your doctor may decide that a biopsy
is needed. For a biopsy, the doctor removes a small sample of tissue
and sends it to a lab to be studied. Endocervical sampling also may be
done. A small brush or other instrument is used to take a tissue sample
from the cervical canal.
In this test, a sample of the endometrium
(the lining of the uterus) is collected for study. Some women with an
AGC result need to have this follow-up test.
Treatment of cervical changes
depends on many factors. CIN 1 usually goes away by itself. For this
reason, CIN 1 in women 20 years and younger is monitored with repeat Pap
tests. No treatment is needed unless there is an HSIL Pap test result.
In women 21 years and older, treatment is not needed unless CIN 1 has
been present for 2 years, the CIN becomes CIN 2 or CIN 3, or there are
other medical problems.
Several techniques are used to
Some risks, such as heavy
bleeding, are associated with some forms of treatment. All treatments
may affect a future pregnancy. Talk to your doctor about these risks
before you are treated. You also need
follow-up testing after treatment, which may involve repeat Pap tests in
6 and 12 months or an HPV test. You should also get regular Pap tests
after the follow-up is done.
Follow-Up Testing for Abnormal Pap Test Results
To use this table, first find
your result on the left side of the table. Then, find the block that
corresponds to your age or reproductive status on the top row of the
atypical squamous cells of undetermined significance; LSIL, low-grade
squamous intraepithelial lesion; HSIL, high-grade squamous
intraepithelial lesion; ASC-H, atypical squamous cells, cannot exclude
HSIL; AGC, atypical glandular cells; HPV, human papillomavirus; LEEP,
loop electrosurgical excision procedure
If you have an abnormal Pap test
result, talk to your doctor about what the result means and the
recomended next steps. Keep in mind that many women with some types of
abnormal Pap test results do not need treatment, only follow-up testing.
It is important to have regular Pap tests to detect these problems. If
treatment is needed, it can be done early enough to prevent cancer
before it develops.
Removal of a small piece of tissue that is then examined under a
microscope in a laboratory.
Intraepithelial Neoplasia (CIN): Another term for
dysplasia; a noncancerous condition that occurs when normal cells on the
surface of the cervix are replaced by a layer of abnormal cells. CIN is
graded as 1 (mild dysplasia), 2 (moderate dysplasia), or 3 (severe
dysplasia or carcinoma in situ).
Viewing of the cervix, vulva, or vagina with magnification using an
instrument called a colposcope.
A noncancerous condition that occurs when normal cells are replaced by a
layer of abnormal cells.
The lining of the uterus.
The use of drugs that produce a sleep-like state to prevent pain during
(HPV): The name for a group of related viruses, some of
which are linked to cervical changes and cervical cancer.
The body’s natural defense system against foreign substances and
invading organisms, such as bacteria that cause disease.
The use of drugs that prevent pain in a part of the body.
Excision Procedure (LEEP): The removal of abnormal tissue
(of the cervix, vagina, or vulva) using a thin wire loop and electric
A test in which cells are taken from the cervix and vagina and examined
under a microscope.
intraepithelial lesion (SIL): The term used in Pap test
results for abnormal growth of cells on the surface of the cervix.