There are several types of adenocarcinoma . About 60 percent are the endocervical cell type, 10 percent are each of endometrioid and clear cell carcinomas and 20 percent are adenosquamous carcinoma.
There are two rare types of cervical cancer known as small cell carcinoma and cervical sarcoma . Both have a poor prognosis .
How It Spreads Most scientists believe that cervical warts or pre-invasive cervical cancer may develop over a period of months or years after the cervix is infected with the human papilloma virus (HPV). This early tumor—known as low-grade SIL (squamous intraepithelial lesion) or as mild dysplasia or cervical intraepithelial neoplasia (CIN) Grade 1—can progress to moderate dysplasia (CIN-2) or high-grade SIL, then to high-grade SIL or severe dysplasia and carcinoma in situ (CIN-3) and eventually to invasive carcinoma. Most physicians believe that about two thirds of all cases of severe dysplasia progress to invasive cancer if left untreated. This transformation takes anywhere from 3 to 30 years, about 10 years on the average.
Once the cervical cancer becomes invasive, it can spread locally to the upper vagina and into the tissues surrounding the upper vagina and the cervix (the parametrium). Eventually it grows toward the pelvic sidewall, obstructing the tubes (ureters) that drain urine from the kidney to the bladder. It can also spread directly to the bladder and rectum.
Cervical tumor cells can invade the lymphatic system and spread to the lymph nodes in the pelvic wall. Eventually they may spread to the iliac lymph nodes higher in the pelvis, the aortic lymph nodes, the nodes above the collarbone and occasionally to the groin nodes.
