How are the results of a Pap test reported?
Most laboratories in the United States use a standard set of terms called the Bethesda System to report test results. Under the Bethesda System, Pap test samples that have no cell abnormalities are reported as “negative for intraepithelial lesion or malignancy. Samples with cell abnormalities are divided into the following categories: • ASC—atypical squamous cells. Squamous cells are the thin flat cells that form the surface of the cervix. The Bethesda System divides this category into two groups: • ASC–US—atypical squamous cells of undetermined significance. The squamous cells do not appear completely normal, but doctors are uncertain about what the cell changes mean. Sometimes the changes are related to human papillomavirus (HPV) infection (see Question 13). ACS–US are considered mild abnormalities. • ASC–H—atypical squamous cells cannot exclude a high-grade squamous intraepithelial lesion. The cells do not appear normal, but doctors are uncertain about what the cell changes mean. AS
A Pap test is reported as normal (negative) when all the cells are of a healthy size and shape. An abnormal (positive) test is reported if any cells of different sizes or shapes are found. An abnormal Pap test does not mean you have cancer. Special terminology is used to describe the degree of abnormal cells. Since 2001, the categories used are: Benign Cellular or Reactive Changes; ASC-US (atypical squamous cells of undetermined significance); ASC-H (atypical squamous cells, cannot exclude high-grade), low-grade SIL (squamous intraepithelial lesion – often referred to as mild dysplasia), high-grade SIL (often referred to as moderate or severe dysplasia) and AGC (atypical glandular cells).
