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Atypical squamous cells of undetermined significance (ASCUS) is a mildly abnormal reading that may occur when a woman gets a PAP smear. Sometimes abnormal squamous cells are found, but their presence don't clearly indicate that there is cancerous or a precancerous state. This type of abnormal reading may mean that the patient will need a few more tests or monitoring PAP smear results over the following years to be certain there is no indication of cervical cancer. In over 80% of cases, ASCUS doesn’t represent a finding of cancer, but it’s still advised that care be taken.
The reading itself, “atypical squamous cells of undetermined significance,” says a great deal about what the test is communicating. That fact that ASC is of “undetermined significance” really says it all. The laboratory analyzing the test can’t tell how important the reading is because its significance is unknown.
Any reading that could have a small indication that cervical cancer might develop suggests additional testing. A woman who has a finding of ASCUS may be asked to undergo a screening for human papillomavirus (HPV) because many forms of it have been linked to cervical cancer. Not all women have this test, especially if they have active vaginal infections of an identified origin that might account for ASCUS result or if they are pregnant, when abnormal readings get pretty common.
There are so many things that cause an atypical squamous cells of undetermined significance result that doctors may not choose to do much. In addition to pregnancy, menstruating when the PAP smear was done or normal sexual activity just before the PAP could cause cells on the cervix to be irritated and to produce thin squamous cells. The latter cause is one reason women are asked not to engage in sexual intercourse the day before a pelvic exam.
Given these normal causes of ASCUS, a lot of doctors just choose to do a repeat PAP smear the following year to see if abnormal results remain. On the other hand, if a woman is reasonably at higher risk for cervical cancer, a finding of atypical squamous cells of undetermined significance might suggest a more extensive form of cervical examination and biopsy called a colposcopy. This can better evaluate the cervix by examining it microscopically, and a doctor could then take small samples of any areas that appear to be of concern.
In most cases, a laboratory result of atypical squamous cells of undetermined significance doesn’t mean much, though it does require some follow-up. Most women may get this result once and never have another abnormal PAP smear again. It is still important to recognize the possible significance of ASCUS and be certain to follow through with doctor recommendations for additional treatments or exams.