Stages in the development of cervical cancer.

1. Normal cervix cells in the basal layer divide and differentiate into quiescent (nondividing) cells.

2. Mutations in basal layer cells may cause them to grow abnormally and enter dysplasia.

3. Left untreated, accumulation of mutations may cause further proliferation, leading to carcinomas in situ.

4. The tumor may become malignant if cells cross the basal lamina and invade surrounding tissues.