Severely abnormal cells are found on the surface of the cervix. Stage 0 cervical carcinoma in situ is usually caused by certain types of human papillomavirus (HPV) and is found when a cervical biopsy is done. If not treated, these abnormal cells may become cancer and spread to nearby normal tissue. Treatment for stage 0 cervical carcinoma in situ may include cryotherapy, laser therapy, loop electrosurgical procedure (LEEP), or cone biopsy to remove or destroy the abnormal tissue. Stage 0 cervical carcinoma in situ is sometimes called high-grade or severe dysplasia. Also called cervical squamous intraepithelial neoplasia 3 and CIN 3.