An abnormal result from a pap test, also known as a pap smear, can be scary. Because the test looks for changes that indicate cervical cancer or precancerous conditions, many women worry that abnormalities indicate the presence of cancer. However, most abnormalities seen in a pap smear are not serious.
Description
A pap test looks at cells taken from the surface of the cervix, the opening to the uterus. Damaged or infected cells look different under the microscope than normal cells, and the degree and type of damage can indicate whether further tests or other procedures are required. The cells lining the cervix are called squamous cells. The results of a pap test are described as a degree of the changes in these cells.
Causes
An abnormal pap test can result from cervical or endometrial cancer. It may also indicate precancerous changes that are not cancer yet. Frequently, an abnormal pap test results from infection with HPV, the human papilloma virus.
Types of Results
Abnormal results are grouped according to the degree of cellular changes, called dysplasia. The most common abnormal pap test result is "atypical squamous cells of undetermined significance," also referred to as ASC--US. This indicates that some abnormal cells were seen, but they are probably not cancerous.
A squamous intraepithelial lesion can be described as low grade or high grade, called LSIL or HSIL respectively. HSIL is more serious than LSIL, but both may indicate the presence of precancerous cells. Sometimes the pap test comes back with a result of atypical squamous cells-cannot exclude HSIL, also called ASC--H. This result means that cellular changes were seen that may be a squamous intraepithelial lesion, but the technician can't definitively determine whether it is or isn't. Atypical glandular cells or AGC indicates possible precancerous cells in the upper cervix, which contains a different type of cell.
Follow Up
The follow up for an abnormal pap test depends on the specific result of the test. Women with ASC--US may be tested for the human papilloma virus, HPV, to determine if this infection is the cause. An ASC--US result also usually requires a repeat test in six months, although women under 20 may be able to wait a year for follow up tests. An LSIL result may be followed up with repeat testing in six months or the patient may be referred for a colposcopy, a visual inspection of the cervix with a magnifying device, at the doctor's discretion. A woman with a pap test result of HSIL or ASC-H typically is referred for a colposcopy or a loop electrosurgical excision procedure, which removes abnormal cells using an electrified wire. An AGC result generally requires HPV testing, colposcopy, endocervical sampling and possibly endometrial sampling.
Importance
Following up on an abnormal pap smear is vital because this test is the most effective way of detecting cellular changes that may indicate developing cervical cancer. Cervical cancer is treatable if caught early.
