FAMILY MEDICINE® COLUMN
By John C. Wolf, D.O.
Associate Professor of Family Medicine®
Ohio University College of Osteopathic Medicine

COLPOSCOPY: THE "GOLD STANDARD" FOR PAP SMEARS

Question: My doctor told me my pap smear was abnormal and has now ordered a colposcopy test, which she says is more accurate. The colposcopy is scheduled for three weeks from now. I have two questions: One, would you explain colposcopy to me? And two, is it safe to wait three weeks to have this test since my pap smear was abnormal?

Answer: First, let me briefly discuss the pap smear, since it was this test that signaled the need for colposcopy. The name of the "pap" test comes from the name of the Greek physician, George N. Papanicolaou (1883-1962), who developed this technique to detect cancer cells. It can be used to evaluate cells obtained from many parts of the body, but is most frequently done to test cells from the uterine cervix the end of the uterus which opens into the vagina. The skin or epithelium, in medical terms of the cervix can develop a type of cancer that has no physical symptoms until it has spread to involve other parts of the reproductive tract or spread to distant parts of the body. So, the "pap" test is done to detect this cancer while it is still small and hasn't spread.

When obtaining the tissue sample for a pap smear, cells are scraped from the opening in the center of the cervix and also from the part of the cervix that faces out toward the vagina. These are the surfaces most likely to develop cancer. However, the sampling of cells is non-specific in that no attempt is made to obtain cells from specific areas that might appear different from the rest of the cervical tissue.

Next, the cells are studied using the pap smear technique and identified as being normal or abnormal. If the tissue is abnormal, then it is further placed into one of several subcategories described by technical terms with meanings that range from "looks a little unusual but not indicative of cancer" all the way to "definitely looks like cancer."

All abnormal pap smears require further evaluation to be sure that cancer isn't present. The least worrisome results may only require a second pap smear performed in a few weeks, but more serious findings require a detailed evaluation of the cervix. The procedure for making that detailed evaluation is the colposcopy your doctor has asked you to undergo. And to quickly answer your question about waiting, the three-week delay is only emotionally difficult for you. It won't alter the treatment you will need to correct the underlying problem.

Now I'll try and explain the procedure of colposcopy. From the patient's end of the table, a colposcopy is much like a pap smear. From the doctor's end of the table, the technique is definitely different. The random sampling of cervical cells done in a pap smear is replaced by very specific sampling of abnormal appearing tissue. The doctor rinses the cervix with vinegar (5 percent acetic acid for those who like professional-sounding terms) to help highlight differences in the cells. Then, aided by the use of a low-power microscope and illumination from a green light, he or she will take small "pinches" of any tissue that looks abnormal. These larger and more specific samples provide sufficient tissue for the pathologist, the doctor who studies these samples under the microscope, to accurately assess the nature of the problem. Once the underlying cause of the abnormal pap smear has been determined by colposcopy, your doctor will then talk with you about any treatment that may be necessary.

Colposcopy is more accurate than a pap smear; in fact, it is the "gold standard" against which the accuracy of the pap smear is compared. With this fact in mind, you may wonder why it isn't routinely used instead of the pap smear. Screening for cancer of the cervix is like many dilemmas in life in that cost is of some significance. Colposcopy takes longer to perform than a pap smear and also requires the use of an expensive colposcope that low-power microscope I mentioned in addition to specialized training. These factors make the cost of colposcopy too great to replace every pap smear.

Family Medicine® is a weekly column. To submit questions, write to John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701.