What Does an ASCUS Pap Smear Result Mean?

An ASCUS Pap smear result means some cells from the cervix do not look completely normal, but the laboratory cannot say whether the changes are caused by HPV or something else. ASCUS stands for atypical squamous cells of undetermined significance. The US National Cancer Institute (NCI) describes it as the most common abnormal Pap test finding.

ASCUS is not a diagnosis of cancer or precancer. It is a signal that the cells need a closer look, usually starting with an HPV test. This guide explains the general follow-up pathways described by official sources. It cannot tell you what your own result means or what you personally need next.

Screening is designed to find cell changes before they cause problems, and an ASCUS result on its own is not a reason for emergency care. Symptoms are a separate matter: if you have them, book an appointment rather than waiting for a routine repeat test that may be months away.

The NHS advises seeing a doctor if you notice any of the following. These symptoms have many possible causes, and most are not cancer, but they should be checked rather than left until your next screening date.

• Vaginal bleeding that is unusual for you, such as during or after sex, between periods or after menopause.
• Periods that are heavier than usual.
• Changes in vaginal discharge.
• Pain during sex, or pain in the lower back, pelvis or lower abdomen.

HPV (human papillomavirus) is a common cause of cervical cell changes. MedlinePlus explains that unclear results can also be linked to pregnancy, menopause or an infection, and that a Pap test can pick up inflammation. Because the cause is uncertain, an HPV test is used to help sort out which explanation is more likely.

MedlinePlus also notes that minor cell changes usually go back to normal on their own. That is one reason many people with ASCUS are offered monitoring rather than treatment.

In the United States, follow-up is guided by the 2019 ASCCP risk-based management guidelines. These look at your current result together with your past screening history, rather than the Pap result alone. A CDC summary of these guidelines describes the following general pathways for people aged 25 and over.

Guidelines are updated over time and your clinician may adjust the plan for your history, pregnancy or other factors. Treat these pathways as background for a conversation, not as a personal plan.

An HPV-related result is not a judgement about you or a partner. The NHS notes that a positive HPV result does not mean a partner has had sex with someone else, and that HPV can be present without recent sexual activity or a new partner.

• HPV-negative ASC-US, with previous results unknown or HPV-negative: repeat HPV testing, with or without a Pap test, in 3 years.
• HPV-positive ASC-US, with previous results unknown or HPV-positive: colposcopy is recommended.
• A minimally abnormal result, such as HPV-positive ASC-US, that follows a negative HPV test or co-test within the past 5 years: the CDC summary says follow-up in 1 year is recommended instead of colposcopy.

Report wording differs between countries. In England, screening starts with an HPV test and the cells are only checked if high-risk HPV is found. UK colposcopy guidance uses terms such as "borderline changes" and "low-grade dyskaryosis" rather than ASC-US, and it states that anyone who is HPV-positive with abnormal cells must be referred for colposcopy.

The NHS explains that if HPV is found along with cell changes, you will be asked to have a colposcopy, and that cell changes will not get worse while you wait for that appointment. Other countries use their own report wording and pathways. If your report uses local terms, ask your clinician how they apply to you.

Age can change the approach. The CDC summary notes that HPV testing after an ASC-US result applies to people aged 25 and over, and that HPV testing is not part of routine screening for people younger than 25. It also notes that HPV infections and cell changes in adolescents are more likely to clear than in older people. If you are under 25, ask your clinician which follow-up applies to you.

Pregnancy can also affect timing. NCI explains that if you are pregnant or planning a pregnancy, your clinician will talk with you about which procedures are recommended and when. MedlinePlus lists pregnancy among the factors that can contribute to an unclear Pap result, so mention it when you discuss your report.

A colposcopy is a closer look at the cervix using a magnifying instrument with a light. NCI describes how a speculum is used, as in a Pap test, and a vinegar-like solution helps abnormal areas show up. A small tissue sample, called a biopsy, is often taken so it can be checked under a microscope.

If you are pregnant or planning a pregnancy, tell the team. NCI says your clinician will talk with you about recommended procedures and their timing, and some treatment may be delayed until after delivery. It is reasonable to ask what the appointment will involve and how you will get the biopsy results.

Bring your full report, including the HPV result and the date, plus any earlier screening results you can find. These questions can help you leave with a clear plan.

• Was an HPV test done on this sample, and was it positive or negative?
• Does my previous screening history change the plan?
• Is my next step a repeat test or a colposcopy, and when is it due?
• Who will contact me, and what should I do if I hear nothing by that date?
• Could pregnancy, menopause or an infection have affected this result?
• Which symptoms should make me book sooner?

On SameCase, patients and verified doctors share de-identified cases. Reading how others with an ASCUS result talked through HPV results, repeat tests or colposcopy can help you notice questions you had not thought to ask.

Other people's cases cannot tell you what your result means or what will happen to you. Use them to prepare for your appointment, and rely on your own clinician for decisions about follow-up.