The Meaning of an Abnormal Pap Smear

It can be scary to get your Pap smear results from your doctor. "Normal" is easy to understand. However, if you have an abnormal Pap smear, it can be difficult to know if the results are anything you need to be worried about. This guide to abnormal Pap smear results will help you understand what your doctor is trying to tell you. The more you understand, the easier it will be to make informed decisions about follow-up care.

A normal Pap smear result means that all the cells in the sample looked the way they should. Additional follow-up is not indicated. You should continue to get tested according to current guidelines.

ASCUS stands for Atypical Squamous Cells of Undetermined Significance. In other words, there are squamous cells that don't look normal. However, those cells are not abnormal enough to be considered dysplasia.

ASCUS is the most common abnormal Pap smear result. It is usually nothing to worry about. Although ASCUS can be caused by an early HPV infection, an ASCUS diagnosis may also be due to irritation from sex or even bad Pap smear technique. Diagnoses of ASCUS will often resolve spontaneously over time with no intervention or treatment.

Follow-up for ASCUS is usually a repeat Pap smear at six months. If that's normal, then no further follow-up is necessary. At that point, a patient can return to the normal screening schedule.

Alternatively, patients diagnosed with ASCUS may be tested for HPV. Then, anyone who is positive for a high-risk type would be sent for further follow-ups, such as colposcopy or LEEP. Guidelines for follow-up vary with age and pregnancy status, but ASCUS does not usually require aggressive follow-up or treatment.

SIL is another common abnormal Pap smear result. The acronym stands for a squamous intraepithelial lesion. Squamous intraepithelial lesions are squamous cells that have been changed in a way that suggests they may eventually become cancerous. This, however, does not mean they will become cancerous. Even without treatment, many cases of SIL will resolve on their own.

Squamous intraepithelial lesion diagnoses can be divided into two types: high grade and low grade. These correlate to CIN 1 and CIN 2 or 3 diagnoses, respectively.

LSIL/CIN 1: Low grade squamous intraepithelial lesions (LSIL) are almost always a sign that a woman has been infected with HPV. This diagnosis also implies that the doctor reading the Pap smear or biopsy has seen signs that look like early-stage pre-cancer.

LSIL diagnoses are relatively common. They often resolve on their own without treatment. In very young women, follow-up is usually a repeat Pap smear in six or 12 months. For older, reproductive-age women, the American College of Obstetrics and Gynecology (ACOG) guidelines suggest colposcopy to determine the extent of the damage. They do NOT necessarily recommend treatment. For post-menopausal women, follow-up may be a repeated Pap smear, HPV test, or colposcopy.

Because LSIL does so often heal on its own, most doctors advocate a less aggressive approach of follow-up rather than treatment. In fact, the ACOG guidelines state that CIN 1/LSIL should not be treated unless it has persisted for more than two years, progresses to CIN 2 or CIN 3, or other medical factors are involved. Over-treatment, however, is still relatively common. Sometimes when people hear the phrase "pre-cancerous cells" they decide they'd rather be safe than sorry, even when the treatment can have significant side effects. 

HSIL/CIN 2-3: High grade squamous intraepithelial lesions (HSIL) are more likely to become cervical cancer than LSIL. However, many of these lesions still regress on their own. Carcinoma in situ, or CIS, is the most serious form of HSIL and the one most likely to progress to cancer. CIS may also be diagnosed as CIN 3.

Guidelines state that every woman who is diagnosed with HSIL by Pap smear should be followed up by colposcopy. During the colposcopy procedure, lesions may be biopsied, or they may be treated by LEEP, conization, freezing (cryotherapy), or laser therapy. For small enough lesions, a punch biopsy may actually be used as treatment.

This complicated-looking acronym stands in for the diagnosis "atypical squamous cells, cannot exclude HSIL." It basically means that the doctors are having trouble making a diagnosis. You might have HSIL, you might not. The doctors can't tell without a further test. Follow-up by colposcopy is recommended.

Atypical glandular cells (AGC) refers to changes to the cervix that do not occur in the squamous epithelium. Instead, abnormal glandular cells were seen in the sample. This result suggests there may be cancer in the upper parts of the cervix or the uterus.

Follow-up for AGC can include colposcopy, HPV testing, and sampling of the lining of both the cervix (the endocervix) and uterus (the endometrium). The choice of follow up depends on what specific types of abnormal cells were seen in the smear. Treatment for AGC, if necessary, is more invasive than treatment for squamous cell lesions.

If you have been diagnosed with cervical cancer, it means that the damage to your cervix is no longer superficial. You will probably be sent to an oncologist for further follow-up and treatment. The extent of treatment will vary by the severity of your cancer.