Atypical squamous cells of undetermined significance indicates that the test revealed slightly abnormal cells that don't clearly suggest the growth of precancerous cells, reports the Mayo Clinic. The doctor might reanalyze the sample and order further testing.
After receiving a sample that showed atypical squamous cells, a doctor is likely to order the sample retested for various viruses, according to the Mayo Clinic. Because some types of human papillomavirus and other viruses can eventually lead to cervical cancer, doctors might order further testing if the sample reveals that the patient has one of these viruses. If the patient has none of these high-risk viruses, these atypical cells are usually not concerning.
While abnormal cells found during a Pap smear often require examination, most positive results are caused by HPV, states WebMD. In most cases, these abnormal cells go away on their own if they're caused by HPV, although it's important to determine which strain the patient has. Other infections can also cause abnormal cell results; yeast and bacterial infections, for example, can cause a positive result, and doctors can prescribe treatments for these infections. Another possible cause of a positive result is simply age, as post-menopausal women might show abnormal growth with no other cause. On their own, abnormal cells don't cause symptoms.