The Papanicolaou test also called Pap smear is a screening test used in gynecology to detect premalignant and malignant (cancerous) processes in the ectocervix. Significant changes can be treated, thus preventing cervical cancer. The test was invented by and named after the prominent Greek doctor Georgios Papanikolaou.
Categories of Pap Tests
There have been many classifications of pap tests, a great deal of confusion occur. It is much simpler to think of the Pap smear as showing one of several things:
- Invasive cancer
- Normal, or a variation of normal, such as "irritation"
- Pre-cancerous changes
- Probably normal, but there are mild changes that you should keep an eye on or evaluate further
No matter which classification system is being used, all Pap smear reports can be thought of as belongs to one of the above group. Years ago pap smears were graded on a scale from 1 to 5, with 1 being normal and 5 being cancer. There was little agreement between labs of what the numbers meant. Although this classification system is out of date, unfortunately some labs still use this reporting system. In order to understand how pap tests are classified, you first need to know a little more about the cervix.
ABNORMAL PAP TEST
Very few experiences can be as frightening as receiving information that your pap smear came back abnormal. Although cervical cancer is the first thing that may comes to mind, most of the time an abnormal pap smear indicates a minor problem with the cervix that may or may not need treatment.
What does the Pap test mean?
Some cells are scraped or brushed off the cervix during a pap smear, and prepared on a slide that can be examined under a microscope. The use of the Pap test is to detect changes that may lead to cervical cancer long before cancer develops. Treatment of Pre-cancer of the cervix is easy and almost always prevents cancer from developing.
Abnormal results are reported according to the Bethesda system. They include:
- Squamous cell abnormalities (SIL)
- Atypical squamous cells of undetermined significance (ASC-US)
- Low-grade squamous intraepithelial lesion (LGSIL or LSIL)
- Atypical squamous cells - cannot exclude HSIL (ASC-H)
- High-grade squamous intraepithelial lesion (HGSIL or HSIL)
- Squamous cell carcinoma
- Glandular epithelial cell abnormalities
- Atypical Glandular Cells not otherwise specified (AGC or AGC-NOS)
Endocervical and endometrial abnormalities can also be detected, as can a number of infectious processes, including yeast, herpes simplex virus and trichomoniasis. However it is not very sensitive at detecting these infections, so absence of detection on a Pap does not mean absence of the infection.