Pap smears can diagnose cervical cancer at a very early stage. Pap smears, which are simple, painless tests that examine cells scraped off the surface of the cervix, should be done every 3 years up until age 65 to 70. Most laboratories grade pap smear results using the Bethesda system, which classifies abnormal cells as squamous intraepithelial lesions (SIL). Squamous cells are cells that cover the surface of the cervix. Of the 55 million pap smears performed in the United States each year, around 6 percent are abnormal, the National Cancer Institute (NCI) states.
ASC
ASC-US, the most common abnormality found on pap tests, stands for "atypical squamous cells of uncertain significance." Human Papillomavirus (HPV), a common sexually transmitted infection, is the most common cause of ASC-US, the American Congress of Obstetricians and Gynecologists (ACOG) reports. A repeat pap smear to monitor cervical cell changes is usually recommended.
ASC-H indicates cells that may have a higher chance of being precancerous. ASC-H stands for "abnormal cells cannot exclude a high grade intraepithelial lesion." Patients who have an ASC-H diagnosis should follow up with a colposcopy, closer examination of the cervix using a special instrument called a colposcope and possible removal of a small section of the cervix for microscopic examination.
SIL
Squamous intraepithelial lesion (SIL) indicates possible precancerous cells, which are further designated as low grade (LSIL) or high grade (HSIL). LSIL nearly always indicates HPV infection and often clears on its own, while HSIL indicates more abnormalities in the cells and a higher likelihood that the cells are precancerous. A diagnosis of SIL necessitates follow up with a colposcopy and may require further treatment.
AGC
AGC stands for "atypical glandular cells." Glandular cells line the inner part of the cervix and lining of the uterus. AGC may indicate a higher risk of cervical cancer, and will require follow up with a colposcopy, according to Family Doctor.
CIN
Pap results may also be differentiated according to the degree of abnormality, or dysplasia, present in the cells. CIN stands for cervical intraepithelial neoplasia. Neoplasia means abnormal cell growth. CIN is designated as 1, 2 or 3, with mild dysplasia graded as 1. CIN 3 indicates severe dysplasia or carcinoma in situ, or CIS. CIS, a type of HSIL, is the type of abnormal cell most likely to become cancer, ACOG reports.
Squamous Cell Cancer or Adenocarinoma Cells
Either of these designations indicates cervical cancer either in the squamous cells of the vagina or cervix or in the glandular cells. Further diagnosis and prompt treatment will be required to keep the cancer from spreading, the Mayo Clinic warns.
