Atypical squamous cells of undetermined significance on cervical papanicolaou smear

Atypical Squamous Cells of Undetermined Significance (ASCUS)

(Content revised 11/2011)

When the cervical screening test shows the presence of ASCUS, it means that the cells are somewhat different from normal cells under microscope but their degree of deterioration is not severe enough for them to be called pre-cancerous cells. Out of every 100 women taking the screening test, about 3 to 5 will have the above manifestation and 50% of whom will have their cells regressed to normal after 4 to 6 months.

The screening test cannot fully reflect the degree of deterioration of the cervical tissues. In fact, among 100 women with abnormal cervical cells, about 5 have severely deteriorated cervical tissue. Therefore, women should have repeat tests every 6 months until two consecutive normal results are achieved. If abnormal cells persist or the condition worsens, referral to specialist clinic for colposcopy will be required. Since the progression from severe deterioration of cervical cells to cancer generally takes about 5 to 10 years, the condition does not pose any immediate threat, please do not worry excessively.

The development of cervical cancer is a long process. The cells of the cervix gradually undergo a series of changes from normal cells to abnormal cells, to mild, moderate, then severe deterioration, and finally to cervical cancer. Apart from continual worsening of cell changes, at any time, the cell changes can also spontaneously regress to normal. However. Even if the cell changes already show severe deterioration, it can still take up to 5 to 10 years before cancer finally appears.

We understand that woman may wish to have a repeat test as soon as possible. As the external layer of cervical cells has been scraped off during the previous smear and the cells take time to grow again (at least 4 to 6 weeks), early re-examination cannot reflect the condition of the cervical cells accurately. Please attend for a repeat test at the scheduled time.

What is colposcopy?

Colposcopy refers to the examination of the vagina using a magnifying glass. The examination procedures can be performed at clinics without anaesthesia and will take about 10 minutes.

Procedures

The doctor will insert the colposcope, stain the vagina and cervix with special medicinal solution and then use the magnifying glass to identify any abnormal lesion. If abnormal lesion is found, the doctor will use an equipment to extract a small piece of the tissue and send it to the laboratory for further analysis. The whole process is painless and therefore there is no need to worry about the procedure.

Don’t panic.  A pap smear is a screening test for cervical cancer and pre-cancer.  The pap test is usually done in conjunction with an HPV test. There are many causes of abnormal pap smears, and most can be managed in the office.  Once your test comes back abnormal, your provider reviews the test results and decides on a plan of action.

What are the different types of abnormal pap test results?

• Atypical squamous cells of undetermined significance (ASC-US)—ASC-US means that changes in the cervical cells have been found. The changes are almost always a sign of an HPV infection. The changes may also be a result of infection or inflammation. ASC-US is the most common abnormal Pap test result.
• Low-grade squamous intraepithelial lesion (LSIL)—LSIL means that the cervical cells show changes that are mildly abnormal. LSIL usually is caused by an HPV infection that often goes away on its own.
• High-grade squamous intraepithelial lesion (HSIL)—HSIL suggests more serious changes in the cervix than LSIL. It is more likely than LSIL to be associated with pre-cancer and cancer.
• Atypical squamous cells, cannot exclude HSIL (ASC-H)—ASC-H means that changes in the cervical cells have been found that raise concern for the presence of HSIL.
• Atypical glandular cells (AGC)—Glandular cells are another type of cell that make up the thin layer of tissue that covers the inner canal of the cervix. Glandular cells also are present inside the uterus. An AGC result means that changes have been found in glandular cells that raise concern for the presence of pre-cancer or cancer.

What testing is done after an abnormal result?

• Colposcopy with or without cervical biopsy—Colposcopy is an in office exam of the cervix with a magnifying device. If an area of abnormal cells is seen, your health care provider may decide that a cervical biopsy is needed. For a biopsy, the health care provider removes a small sample of tissue and sends it to a lab for testing. The lab tests can determine whether abnormal cells are present and, if so, how severe.
• Endocervical sampling – A small brush or other instrument is used to take a tissue sample from the cervical canal.
• Endometrial sampling— In the case of an AGC result, a sample of the endometrium (the lining of the uterus) may be collected for study using an instrument which looks like a small straw.

What are the potential results of the biopsy?

• Cervical intraepithelial lesion (CIN) is used to report cervical biopsy results. CIN is graded as 1, 2, or 3.
• CIN 1 is used for mild (low-grade) changes in the cells that usually go away on their own without treatment.
• CIN 2 is used for moderate changes.
• CIN 3 is used for more severe (high-grade) changes.
• Moderate and high-grade changes can progress to cancer. For this reason, they may be described as “pre-cancer,” and are usually treated.

How are abnormal cervical cells treated?

• Loop electrosurgical excision procedure (LEEP)—A thin wire loop that carries an electric current is used to remove abnormal areas of the cervix. This procedure can be done in the office or in the operating room.
• Conization—A cone-shaped piece of the cervix that contains the abnormal cells is removed. This procedure must be done in the operating room.

These procedures are usually curative.  Once complete, patients are asked to come in for a follow up visit two weeks after the procedure to review pathology results and to form a plan for future testing.

Information adapted from ACOG Patient Information FAQ 187

What can cause atypical squamous cells of undetermined significance?

How often are atypical squamous cells cancer?

Do atypical squamous cells go away?

Does ASCUS Pap mean cancer?