What is ASCUS?

ASCUS stands for “atypical squamous cells of undetermined significance,” which is a way of saying that a selection of biopsied cells appears slightly abnormal, but that the significance of the finding is not known. This term comes up most commonly in reference to the results of a Pap test, and while it may sound alarming, it usually is not a reason for worry. A number of things can cause an ASCUS result, and this very common result is the most mild type of abnormality.

In a Pap test, a doctor takes a small swab of cells from the cervix and sends them to a laboratory for testing. A normal Pap result indicates that there were no abnormalities in the sample. An ASCUS result indicates that abnormalities were found, but they are not very serious. In other instances, advanced abnormalities may suggest that someone has the Human Papilloma Virus (HPV), a case of cervical cancer, or another medical problem.

Usually, an ASCUS finding is caused by mild inflammation or irritation around the cervix. This causes the cells to look slightly abnormal, but not abnormal enough to be mistaken for the early signs of cancer. People can also receive an abnormal result if they have recently used tampons or had intercourse, as the cervix may be slightly irritated from these activities.

If a woman has never had an abnormal Pap result before, a doctor may decide that the Pap test should simply be repeated in a year to test for abnormalities. If abnormal results have been returned in the past, however, the doctor may ask for a repeat test sooner, to see if more conclusive results can be obtained. A colposcopy may also be recommended, allowing the doctor to magnify the area of interest to look for potential abnormalities and take a sample, if necessary.

If the inflammation is the result of a sexually transmitted infection, the doctor will typically recommend a course of treatment for the infection to resolve the inflammation. If the Pap test is repeated once the infection has been dealt with, the result is usually normal, indicating that the abnormality was benign in nature.

While one's first reaction on hearing that the results of a Pap smear are abnormal may be to panic, an ASCUS result is not a reason for concern. Most typically, the abnormality is totally benign, and it will resolve on its own. Repeated ASCUS results can be an indicator that a problem may be developing, requiring closer monitoring, but they can also be the result of flukes in the laboratory, or a bad sample.