| Modified by: Lara Bonner Millar, MD
By: Ivor Benjamin, MD and Linda Echols, MSN, RN
|Abramson Cancer Center of the University of Pennsylvania|
| Last Modified: March 12, 2012
You have been informed that your recent Pap smear showed some changes in the cells of your cervix and you need further testing. This document will help you understand the cervical cell changes and the probable course of management.
What is a Pap Test?
The Pap test, also called a "Pap smear" was introduced as a screening test for cervical cancer in 1943 by Dr. George Papanicolaou, for whom the test is named. The Pap test examines cells from the cervix, which is located at the top of the vagina. The American College of Gynecology recommends testing at age 21 and if normal, then every 2 years thereafter. However, those age 30 and over who have had three consecutive negative (i.e., normal) test results may be screened once every 3 years.
Normal vaginal discharge contains cells that are shed from the cervix and uterus. Samples of these cells are taken for the Pap test. For this reason, you should not douche, have vaginal intercourse, use tampons or vaginal medication for 48 hours before the Pap test is done.
During the gynecologic examination, a speculum is inserted into the vagina so that the cervix and vagina can be seen. The doctor or nurse inserts a cotton-tipped swab or gentle cytobrush into the cervical opening (cervical os) to sample endocervical cells (which come from the area most at risk for cervical cancer). Next, the examiner gently scrapes the outside of the cervix (portio) with a small spatula in order to get samples of the discharge containing cervical cells.
These samples are sent to a pathologist for detailed examination under a microscope. A report is sent to your doctor with a classification of the test results and a description of the cell changes. An HPV test, looking for certain strains of the HPV virus associated with cervical cancer, can also be sent with this sample. This is done by obtaining cervical cells in the same manner as is done for a Pap smear. This test is often routinely done at the time of a Pap smear, or alternatively as a follow-up test after an abnormal Pap smear.
Process of Cervical Changes
The cervix is the part of the uterus that extends into the vagina. There are two types of cells that line the cervix, one lines the outer cervix (portio) and another lines the inner cervix (endocervix). There is a distinct junction between the two cell types called the transformation zone. The Pap test is taken from this area because this where dysplasia (pre-cancer) and cancer most often arise.
Two common changes in cells are metaplasia and dysplasia.
Metaplasia - Metaplasia is generally described as a process of cell growth or cell repair that is benign (not cancerous). This process normally occurs in unborn babies, during adolescence, and with the first pregnancy. Studies have shown that metaplasia is present in more than one half of all women at some point in their development. This is a normal finding and does not indicate cancer.
Dysplasia - In dysplasia, there is an increase in the number of cells formed, which do not mature as expected. This changes the inside of the cell. The higher the grade of dysplasia found on the cervix, the more likely that it will progress to invasive cancer. For this reason, dysplasia is thought of as a "pre-cancerous" condition. Dysplasias are nearly 100% curable if managed appropriately. Although some mild dysplasias (LSIL) will regress without treatment, it is not possible distinguish between dysplastic areas of the cervix that will return to normal and dysplastic areas which will progress and ultimately become cancer. In turn, these results necessitate further testing.
Causes of Cervical Cell Changes
Inflammation often results in mildly abnormal Pap tests resulting in the diagnosis of ASCUS in the Bethesda System or changes consistent with Human Papilloma Virus (HPV) infection. An inflamed cervix may appear red, irritated, or eroded. Some of the common causes of cervical inflammation are:
When the inflammation is treated and cleared, repair through metaplasia usually will follow. In several months, a repeat Pap test will often then be normal.
Classification of Squamous Cells on the Pap Test
Several different classification schemes have evolved over the years for characterizing Pap test results. Unfortunately, this is a continuing source of confusion. The most commonly used classification scheme is the Bethesda System.
Classification of Glandular Cells on the Pap Test
Glandular cells, which produce mucus, are found in the opening of the cervix and in the uterus. Abnormalities in these cells are more difficult to classify. Glandular cells that are seen on the Pap test most commonly come from the endocervix (area closest to the uterus). However, other glandular epithelial surfaces in the female reproductive tract may shed cells that are visible on the Pap test. Endometrial cells may also appear on Pap tests and reveal underlying abnormalities. Because the female reproductive tract is open to the abdominal cavity via the Fallopian tubes, occasionally, cells from the ovary, Fallopian tubes, peritoneum or other interabdominal organs may be seen on the Pap smear. Glandular cells on the the Pap test are classified as follows:
Colposcopy: The next diagnostic step
All abnormal Pap smear result often requires further evaluation. If the abnormality is minor (i.e. inflammation, or HPV changes) your healthcare provider may choose to repeat the Pap test in a few months, as your own immune system may "clear" the HPV infection and a follow up Pap be normal. If the abnormalities have persisted or worsened, colposcopy is indicated. Colposcopy will enable your physician or nurse to make a more accurate diagnosis.
Colposcopy - A colposcope is a lighted microscope that is used to magnify the cervical tissue during a pelvic examination. The colposcope is used to visualize abnormal areas of the cervix and vagina that are too small to see with the naked eye. The entire transformation zone must be seen. The colposcopic examination is an office procedure and may be a bitmore uncomfortable than a routine pelvic examination because of the pressure from the speculum lasting longer than a typical Pap test. The test takes 5 to 10 minutes to perform. During the examination, the examiner may take small samples of cervical tissue (biopsies), which are later examined by a pathologist. These diagnostic biopsies will guide further management.
Treatment Options for Cervical Dysplasia
Cone Biopsy - A cone biopsy is a minor operation, which is usually performed in an outpatient surgical facility. In the operating room, the physician removes a small cone shaped tissue sample from your inner cervix. This tissue is sent to a pathologist for detailed examination under a microscope. This procedure does not remove any of your reproductive organs and should have little impact on your future ability to become pregnant. If only dysplasia is found in the cone specimen, then often no additional treatment will be required. However, if invasive cancer is discovered, additional treatment (i.e. surgery or radiation therapy) is indicated. Therefore, a cone biopsy may be considered as therapeutic (if all of the dysplasia is removed) or diagnostic (if it discovers a worse problem that requires additional treatment).
Loop Electrosurgical Excision Procedure (LEEP) - The LEEP procedure is similar to a cone biopsy in that it removes a tissue sample from your cervix, which is then examined, under a microscope, by a pathologist. It may also be called a LLETZ (large loop excision of the transformational zone). The LEEP procedure uses a low voltage, electric wire to cut away the abnormal area and has the advantage of being easily performed in the office with local anesthesia. However, the LEEP procedure and cone biopsy are not equivalent and your physician will recommend which is the best option, depending on your case.
Cryosurgery - Cryosurgery is another treatment option that can be performed in the doctor's office. During the procedure, the doctor freezes and thereby destroys the dysplasia on your cervix. You may notice a brief unpleasant cold sensation during the freezing procedure. A disadvantage of cryosurgery is that no specimen is obtained for the pathologist to examine in order to exclude the possibility of invasive cancer.
References & Further Reading
Wright T, Massad L, Dunton C, et al. 2006 Consensus Guidelines for the Management of Women with Abnormal Cervical Cancer Screening Tests. American Journal of Obstetrics and Gynecology (2007;197(4):346-355).