The cervix is the lower cone-shaped portion of the uterus, and is part of the female reproductive system. Cervical cancer is diagnosed in 11,000 women a year in the United States, according to the National Cancer Institute. Many more women have pre-cancer of the cervix, meaning there are abnormal cells on the surface of the cervix that have not yet begun to divide uncontrollably. There are a few main types of cervical cancer, which are named based on which cells of the cervix are the origin of the cancer.
Squamous Cell Carcinoma
Squamous cell carcinoma is the most common type of cervical cancer, accounting for 80 to 90 percent of all cases of cervical cancer, according to the American Cancer Society. Squamous cells look flat and thin when examined with a microscope. The cervix can be divided into two portions: the exocervix, which is the outer portion of the cervix; and the endocervix, which is the inner portion of the cervix. The cells that transform into squamous cell carcinoma are usually located where the exocervix meets the endocervix; these cells line the bottom of the cervix.
Adenocarcinoma
Another type of cell that composes the cervix is a glandular cell that secretes mucus into the vagina. When the glandular cells are the origin of the cancerous cells, the cancer is called adenocarcinoma, according to the Mayo Clinic. The American Cancer Society notes that these cells are located in the endocervix. This type of cancer accounts for 10 to 20 percent of all cervical cancers. The incidence of cervical adenocarcinoma is increasing in women born in the last 20 to 30 years.
Adenosquamous Carcinoma
According to the American Cancer Society, this form of cervical cancer is much more rare than squamous cell carcinoma or adenocarcinoma. Adenosquamous carcinoma, also called mix-cell carcinoma, has features of both squamous and glandular cells, as determined by microscopic examination.
