The uterine cervix is actually an epithelium with a basement membrane underneath, and precancerous lesions that do not penetrate the basement membrane are called carcinoma in situ. Carcinoma in situ is usually referred to as squamous carcinoma. If the main manifestation has a glandular epithelial component, it may be judged as adenocarcinoma in situ of the cervix in the pathological diagnosis mainly because of the proximity to the cervical canal area. Adenocarcinoma in situ of the cervix is actually similar to carcinoma in situ of the cervix, except that it has an adenocarcinoma component. In a sense, adenocarcinoma in situ of the cervix is not considered to be cervical cancer, but a precancerous lesion. Adenocarcinoma in situ of the uterine cervix is actually a pathological diagnosis without too many different clinical symptoms and can only be given at the time of pathological diagnosis. Carcinoma in situ and adenocarcinoma in situ may have different treatment strategies, for example, when conization may be done for adenocarcinoma in situ, it needs to be judged whether to perform deep incision or not, to prevent lesions with cervical canal from being missed. Therefore, the difference between carcinoma in situ and adenocarcinoma in situ has significance in treatment, but there are no special symptoms and no special presentation for patients.