Pap smears are often performed as part of a normal gynecolgical exam to look for signs and risk factors for cervical cancer. With a Pap smear, a cotton swab is inserted into the vagina and brushed up against the cervix in order to get a sampling of the cervical cells. A Pap smear is used to diagnose if any of these cervical cells are abnormal, which can be a risk factor for cervical cancer.
Abnormal Cells and Cancer
One of the reasons why Pap smears are performed is to screen women for cervical cancer, according to Medline Plus, a website of the National Institutes of Health. Pap smears are designed to detect unusual cells on the lining of the cervix. Abnormal cells on a Pap smear test can indicate cervical dysplasia, a condition which can lead to cervical cancer.
Frequency
Approximately 55 million Pap smears are done each year in the United States, according to the National Cancer Institute. Roughly 3.5 million, or 6 percent, of these reveal abnormal cells. Abnormalities found during a Pap smear require further followup to determine the cause.
Abnormal Cell Classification
Abnormal cells found on a Pap smear can be classified into several types, according to Family Doctor.org, a website of the American Academy of Family Physicians. A result of atypical squamous cells, or ASC, indicates cells on the surface of the cervix are abnormal. These abnormalities may be classified as "with uncertain significance" or a more serious problem known as an epithelial lesion may be suspected. AGC stands for atypical glandular cells, which are mucus-producing cells. Other abnormal results on a Pap smear may be termed low- and high-grade squamous epithelial lesions, which means that the cells found are different in shape and size. High-grade lesions have cells that are very unusual looking and are likely to lead to cervical cancer.
Causes
There are a number of conditions that can cause abnormal cells to appear on a Pap smear, according to AmericanPregnancy.org. Recent sexual activity, for example, can cause abnormal Pap smears, as can a urinary tract infection, trichomoniasis, a bacterial infection, and infection by human papillomavirus, or HPV, the most common sexually transmitted virus in the U.S., according to the U.S. Centers for Disease Control and Prevention (CDC). Abnormal cells, however, do not necessarily mean that the patient has or could develop cervical cancer. Definitive diagnosis of the abnormal cells requires further testing.
Followup
A colposcopy, according to Family Doctor, is one of the more common ways that abnormal cells in a Pap smear can be further examined. This test uses a special device called a colposcope, which is similar to a microscope. This allows physicians to examine the abnormal cervical cells in more detail and take a tissue sample if needed for further analysis.
