Abnormal Pap test results have been classified using different medical terms. In North America, abnormal cells are now classified according to their degree of abnormality using the Bethesda system (TBS). Other classification systems may still be used in other parts of the world.

Dysplasia

Dysplasia is another term for abnormal cell changes on the surface of the cervix. One system of classification uses dysplasia to identify cell changes, which are classified as:

• Mild: Cells may return to normal without treatment.
• Moderate: Cells may return to normal but more commonly progress to a more serious condition.
• Severe: Cell changes are severely abnormal but not yet cancerous.

All types of dysplasia require monitoring or treatment until repeat Pap tests are normal.

Cervical intraepithelial neoplasia (CIN)

Changes in cells on the surface of the cervix are known as cervical intraepithelial neoplasia (CIN).

• CIN is not cancer. It is a condition in which cervical cells show some change and no longer look normal.
• Untreated CIN may progress to cancer of the cervix.
• The CIN system is very similar to the dysplasia classification system.

The CIN system classifies abnormal Pap tests and interprets biopsy results by number.

• CIN 1: Cell changes are mildly abnormal.
• CIN 2: Cell changes are moderately abnormal.
• CIN 3: Cell changes are severely abnormal but not yet cancerous.