Cervical cancer occurs in the cells of the cervix — the lower part of the uterus that connects to the vagina. The most common type of cervical cancer is squamous cell carcinoma which begins in squamous cells (thin, flat skin cells) on the wall of the cervix. However, some cervical cancers are adenocarcinomas (cancers that begin in cells that make mucus and other fluids). While most cervical cancers are squamous cell carcinomas, both types of cells may be involved in cervical cancer in some instances. Very rarely, cancer occurs in other cells of the cervix.