Cervical Cell Changes on a Pap Test

Cervical cell changes are classified according to their degree of abnormality using the Bethesda system (TBS). Further evaluation decisions are guided by the kinds of changes seen in the cells.

Minor cell changes

Minor cell changes may go away without treatment. But sometimes they turn into more serious cell changes. Types of minor cell changes include:

• Atypical squamous cells (ASC). They may be caused by an HPV infection. Or they may be caused by inflammation, another infection, or atrophic vaginitis. ASC is further classified as:
  • ASC-US: This stands for ASC of undetermined significance. These changes usually stay the same or return to normal.
  • ASC-H: This stands for ASC that cannot exclude high-grade squamous intraepithelial lesions (HSIL). These changes have a higher risk of being more serious.
• A low-grade squamous intraepithelial lesion (LSIL). This is also called mild dysplasia. This change is usually caused by HPV and may become more severe over time. But most cases stay mild or return to normal.

Moderate to severe cell changes

Moderate to severe cervical cell changes (also called moderate to severe dysplasia) mean cell changes that are more likely to be precancerous and develop into cervical cancer if left untreated. Moderate to severe cervical cell changes are classified by the Bethesda system (TBS) as HSIL or as atypical glandular cells (AGC). Follow-up evaluation is needed, and treatment may be needed.

All abnormal Pap tests require follow-up to identify development of more severe cell changes, including cervical cancer. Most abnormal cells can be removed or destroyed before they become cancerous.