Atypical Squamous Cells of Undetermined Significance (ASCUS)

No woman wants a positive result on a Pap test. A positive result means further testing may be needed, and there is the possibility that those tests could result in a cervical cancer diagnosis. The silver lining, however, is that a positive result revealing abnormal or precancerous cells also means that a definite diagnosis can be made and treatment can begin.

When caught early, cervical cancer is curable. Far worse outcomes may result if the test reveals atypical squamous cells of undetermined significance (ASCUS) and the results are misread or the doctor does not proceed with further testing. A treatment delay can mean invasive cervical cancer develops, potentially leading not only to infertility and the necessity for harsher therapies such as radiation and chemo, but possibly fatal consequences.

For information about seeking compensation for damages sustained as a result of a misread Pap test, reach out to a professional attorney today.


Squamous cells are flat and thin cells that grow on top of a healthy cervix. According to the Mayo Clinic, when it comes to atypical squamous cells of undetermined significance (ASCUS), a Pap test may reveal “slightly abnormal” squamous cells, but such changes do not necessarily mean that precancerous cells are present.

Of all abnormal findings in a Pap test, ASCUS is the most common, with approximately 2 million women a year in the U.S. receiving the news that they have such cells in their cervix. What a doctor should do if the Pap test reveals ASCUS is look again at the sample and see if viruses are present, especially the human papillomavirus (HPV). ASCUS may also appear in women with low hormone levels and those with benign growths, such as cysts or polyps.

The presence of HPV is linked to cervical cancer. If no HPV cells are found, additional testing should be done every three years, according to CDC guidelines. If HPV cells are found, the doctor should perform a colposcopy and biopsy. This procedure involves using a colposcope, which is a lit magnifying instrument, for an examination of the cervix, along with the vagina and vulva.

The doctor would typically perform a biopsy at the same time, taking tissue or cell samples so a technician can examine the sample under a microscope.

ASCUS Progression to Cervical Cancer

Without prompt treatment or close monitoring, about 0.25 percent of women with atypical ASCUS develop cervical cancer within two years. Of course, that means that more than 99 percent of women do not develop cervical cancer within that timeframe, but that is little comfort for those who are diagnosed with the disease.

Women who are not treated because of mistakes made by the laboratory or the doctor in reading their Pap test are more likely to develop cervical cancer within this time period. While only a small percentage of women with ASCUS develop cervical cancer, roughly half of all cases of CIN-2 and CIN-3—abnormal cells that may eventually become cervical cancer—are found in women with ASCUS.

False Negatives

Unfortunately, Pap tests have a high percentage of false negative results. That means the test does not indicate ASCUS or other precursors to cervical cancer, when they actually exist. These false negatives may result from the test itself, but just as often result from negligence on the part of the healthcare provider or technician interpreting the test.

Learn More About ASCUS

If you or a loved one had a positive atypical squamous cells of undetermined significance (ASCUS) on a Pap test and it was either misread or no follow-up was done, and cervical cancer later developed, an experienced medical malpractice lawyer may be able to help. An attorney can help you build your claim as well as calculate the amount you should be compensated for. Call today to make an appointment for a free initial consultation.