Understanding ASCUS and Cervical Dysplasia on Pap Tests

When you receive a result slip saying "ASCUS" or "cervical dysplasia" after a Pap (cervical cytology) test at a health checkup or gynecology visit, many people immediately think of cancer and grow anxious. In the clinic, there are quite a few cases of people coming in startled after receiving results elsewhere. To put the conclusion first, ASCUS is not cancer but is closer to "a borderline finding that needs a slightly closer look." In this article, I will calmly lay out the meaning of the test result and the subsequent follow-up process.

Cervical cytology is a test in which cells from the surface of the cervix are collected with a brush and the changes are examined under a microscope. The results are usually divided into normal, changes of uncertain significance, and intraepithelial lesions by degree. In the internationally widely used Bethesda classification, they are representatively divided as follows.

• ASCUS: atypical squamous cells of undetermined significance. A stage that is ambiguous to call normal but does not reach the criteria for a clear lesion
• LSIL: low-grade squamous intraepithelial lesion. Usually a mild change caused by HPV infection that often resolves spontaneously
• HSIL: high-grade squamous intraepithelial lesion. A change more advanced than LSIL, a stage requiring precise confirmation

ASCUS is the most commonly reported abnormal finding among these. The American College of Obstetricians and Gynecologists (ACOG, 2021) describes ASCUS as "the most common abnormal cytology result." Rather than concluding exactly whether it is cancer, you can understand it as a signal that needs one more confirmation.

Most cervical cell changes are related to HPV (human papillomavirus) infection. HPV is a virus common enough that any sexually active woman may encounter it at some point in life, and the vast majority disappear naturally through our body's immunity. However, if high-risk-group HPV infection persists for a long time, cervical cells can change gradually.

So when an ASCUS result comes out, it leads to a flow of not simply looking at cell shape but also confirming together "is this change due to high-risk HPV." In my clinical experience, once people understand this link, vague fear is considerably reduced. It is important not to immediately equate HPV infection itself with cancer. In relation to this, it also helps to look at the relationship between HPV infection and cervical cancer.

International guidelines recommend approaching post-ASCUS management in stages according to "risk." In the risk-based management guidelines of the American Society for Colposcopy and Cervical Pathology (ASCCP, 2019), the reflex HPV method, which uses an HPV test together with the ASCUS result, is widely used.

Colposcopy is the process of magnifying the cervix to look at it in detail, and biopsy is the procedure of confirming a small amount of tissue from a suspicious area. The actual test and follow-up interval can vary depending on whether inflammation or infection is accompanied, whether you are pre- or post-menopausal, and your prior test history, so there are individual differences.

The part many people are most curious about is "does this state keep getting worse." Fortunately, a substantial portion of changes confirmed as ASCUS are reported to recover to normal cells during the follow-up observation process. Some may stay as they are or change to a low-grade lesion, and cases that progress further are relatively few.

What matters is not to be elated or depressed over a single result slip, but to keep up the recommended follow-up schedule without missing it. By confirming the direction of change through follow-up testing, you can manage it sufficiently without excessive anxiety. That said, if abnormal vaginal bleeding or new symptoms arise between tests, it is better to get care regardless of the schedule.

The ASCUS experience actually becomes an occasion to reconfirm the importance of regular screening and prevention. Korea's national cancer screening provides cervical cytology to women aged 20 and older on a set interval, so it is recommended to receive it periodically even without symptoms (Korea Disease Control and Prevention Agency, national cancer screening recommendation).

On the prevention side, the HPV vaccine is cited as a key axis. The World Health Organization (WHO, 2020) presented a cervical cancer elimination strategy bundling vaccination, screening, and treatment, and emphasized the role of vaccination. The Korean Society of Obstetrics and Gynecology likewise recommends the vaccine together with regular screening. It is good to keep the following points in mind.

• Even if you have been vaccinated, keep up regular cytology as before
• Even if HPV has already been confirmed, check whether vaccination is possible through a visit
• Combine everyday prevention habits such as condom use

If you want to comprehensively check your cervical health, you can refer to HPV and cervical cancer focused management or the guide on cervical cancer screening intervals.

ASCUS is not a cancer diagnosis but a borderline finding that needs one more step of confirmation. By gauging risk with an HPV test, looking precisely with colposcopy and biopsy if needed, and following up at the recommended interval, it can mostly be managed stably. Rather than being too startled by a single result slip, I recommend calmly taking the next steps. If the interpretation of the test result or the follow-up schedule is confusing, organize your questions through a remote consultation anytime.

Written by: Lee Dong-hee Director · OB-GYN specialist · View doctor profile

First published November 2, 2023 · Last reviewed May 30, 2026

References: ASCCP 2019 Risk-Based Management Consensus Guidelines (2019), ACOG Abnormal Cervical Cancer Screening Test Results (2021), WHO Global Strategy to Accelerate the Elimination of Cervical Cancer (2020), Korea Disease Control and Prevention Agency national cancer screening recommendation

This article is intended to provide general health information and does not replace individual diagnosis or treatment. If you have symptoms, please consult through a medical visit.