Just as the female parts of a flower contain a stigma which receives pollen, human female reproductive parts have at their center a cervix, which is the bulbous opening to the uterus. Cervical tissue is delicate and made up of thin layers that grow fast and normally heal rapidly. However, chronic inflammation may cause abnormal cell growth that can lead to cancer. Scraping cells from the cervix to detect abnormal growth is the purpose of a pap test, or pap smear. Cellular abnormalities are graded into classifications, which may have various causes.
Inflammation
The most common abnormal pap results are atypical squamous cells of undetermined significance, or ASC-US. Another result indicating low-grade inflammation is squamous intraepithelial lesion, or LSIL. These are most likely caused by minor infections that can either be easily treated or that will go away by themselves. The usual recommendation is to repeat the pap smear every six months until there are two consecutive normal results, and then return to an annual screening.
Human papillomavirus (HPV)
Human papillomavirus (HPV) infection includes more than 100 organisms, some 35 of which are sexually transmitted and cause infection of the vagina, vulva, and cervix. Genital warts are not associated with cancer, even though they are caused by HPV. According to the American College of Obstetricians and Gynecologists (ACOG), most HPV infections are resolved by the woman's immune system and do not require treatment. HPV infection can cause squamous intraepithelial lesion (SIL) of the cervix that ACOG asserts is almost always the cause of abnormal pap results, including those that are mild or low grade.
Factors that impair immune function, such as HIV infection, smoking, poor diet and long term use of oral contraceptives have been found to increase the risk of HPV infection which doesn't go away. The longer a woman is infected with some types of HPV, the greater her risk of developing cervical cancer. Tests to determine the type of HPV infection can be done on cells that are harvested during the pap test.
Cancer
When pap findings are of a more serious type, such as high-grade squamous intraepithelial lesion (HSIL), atypical squamous cells that could be HSIL (ASC-H), or atypical glandular cells (AGC), the likelihood of cancer is stronger and more testing is warranted. A colposcopy allows doctors to look more closely at cervical tissue and to take a biopsy if necessary. Treatment may be suggested to remove cells that are precancerous, or moderate to severe cervical intraepithelial neoplasia (CIN). These treatments may impact future pregnancies.
According to the American Cancer Society, there are two main types of malignancies affecting the cervix. Squamous cell carcinoma is found in 80 to 90 percent of cancers, affecting the outer layer, or ectocervix. Inside the cervical canal, or endocervix, are mucus producing glandular cells. Cancer in these cells is called adenocarcinoma. Women born betweeen 1970 to 1980 have a higher incidence of this type. Rarely, cancer cells have features of both types and are called mixed, or adenosquamous carcinoma.
