|Ivor Benjamin, MD and Mary Rubin, RNC, PhD, CRNP|
|University of Pennsylvania Cancer Center and University of California|
| Last Modified: March 24, 2002
You have been informed that your recent Pap smear showed some changes in the cells of your cervix. This needs further study. This document will help you understand the changes and the probable course of management.
What is a Pap Test?
The Pap test was introduced as a cervical cancer screening test in 1943 by Dr. George Papanicolaou, for whom it is named. The Pap test examines cells from the cervix, or the mouth of the womb that is located at the top of the vagina.
Normal vaginal discharge contains cells which are shed from the cervix and uterus. Samples of these cells are taken for the Pap test. For this reason, you should not douche or use tampons or vaginal medication for at least 24 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. Next, the examiner gently scrapes the cervix the outside of the cervix (portio) with a small spatula in order to get samples of the discharge containing cervical cells.
These samples are placed on one or two glass slides, and are sent to a cytologist for detailed examination under a microscope. A cytologist is a specialist, who is trained in the interpretation of Pap tests. A report is sent to your doctor with a classification of the test results and a description of the cell changes.
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 The outdated Class system originally developed by Papanicolaou has been replaced by the CIN grading system and the Bethesda System. CIN stands for cervical intraepithelial neoplasia and implies an underlying aberration in proliferation of cells. In most cases, this is a precancerous lesion that is easily treated with nearly 100% cure. Both the CIN grading system and the Bethesda System are in widespread use today. The table below compares the various nomenclature used to classify squamous cell abnormalities seen on Pap test:
Classification of Glandular Cells on the Pap Test
Glandular abnormalities are more difficult to classify. Glandular cells that are seen on the Pap test most commonly come from the endocervix. However, other glandular epithelial surfaces in the female reproductive tract may shed cells that are visible on the Pap test. Endometrial cells may 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:
Process of Cervical Changes
The cervix is the part of the uterus that extends into the vagina. There are two types of cells which 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 which 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.
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 as a "pre-cancerous" condition. Dysplasias are nearly 100% curable if managed appropriately. A small proportion of mild dysplasias (CIN I or low-grade SIL) will regress without treatment. However, 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.
Causes of Cervical Cell Changes
Inflammation often results in mildly abnormal Pap tests. These may result in the diagnosis of CIN I in the CIN grading system, 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.
Colposcopy: The next diagnostic step
All abnormal Pap smears require 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. 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 which are too small to see with the naked eye. The entire transformation zone must be seen. The colposcopic examination is an office procedure and is no more uncomfortable than a routine pelvic examination. It takes 5 to 10 minutes to perform. During the examination, the examiner may take small samples of cervical tissue (biopsies). Another specialist, a pathologist, will examine the tissue samples and cells. 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 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. Likewise, a pathologist examines the tissue under a microscope. The LEEP procedure 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 in your case.
Cryosurgery - Cryosurgery is another treatment option. This procedure is done 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.