Cervical intraepithelial neoplasia is most commonly seen in women of childbearing age. A lot of epidemiological data show that early age of sexual debut, multiple sexual partners, multiple births, history of oral contraceptives and certain viral infections are high-risk factors for cervical intraepithelial neoplasia, among which viral infections related to cervical intraepithelial neoplasia include herpes simplex virus II (HSV-II), HPV and HIV, especially HPV infection, which is the main cause of cervical precancer and cervical cancer occurrence and development. It is the main cause of cervical precancer and cervical cancer development. The pathological features of cervical intraepithelial neoplasia Cervical epithelial atypical hyperplasia mainly originates from the reserve cells under the cervical columnar epithelium, which are affected by various external adverse factors, and the series of abnormal changes involving the cervical epithelium from normal, hyperplasia to carcinoma were collectively called cervical intraepithelial neoplasia by Richard in 1967, and the CIN classification was used to reflect the degree of cervical epithelial abnormality. The degree of cervical epithelial abnormality is reflected by CIN grading. According to the degree and extent of atypical hyperplasia, cervical intraepithelial neoplasia can be classified into CIN grade I (mild atypical hyperplasia), CIN grade II (moderate atypical hyperplasia) and CIN grade III (severe atypical hyperplasia and carcinoma in situ). CIN grade I refers to nuclear heterogeneous cells (i.e. cells with thickened nuclear chromatin, abnormal nucleoplasmic ratio, increased mitotic index, etc.) involving 1/3 of the squamous epithelium; CIN grade II refers to nuclear heterogeneous cells involving 2/3 of the squamous epithelium; CIN grade III refers to loss of epithelial stratification, disorganized cell arrangement, loss of polarity, nuclear heterogeneous cells involving more than 2/3 of the squamous epithelium but not reaching the whole epithelium; CIN grade III refers to loss of epithelial stratification, disorganized cell arrangement, loss of polarity, nuclear heterogeneous cells involving more than 2/3 of the squamous epithelium but not reaching the whole epithelium. CIN III (carcinoma in situ) refers to the involvement of nuclear heterogeneous cells in the whole layer of squamous epithelium, but the basement membrane remains intact. Clinical diagnosis and treatment of cervical intraepithelial neoplasia 1. Clinical diagnosis: The main symptoms of CIN patients are increased vaginal discharge, sometimes accompanied by bloody discharge or contact vaginal bleeding. Some patients may have different degrees of lumbosacral pain or abdominal cramps. The cervix may have different degrees of erosion-like, hypertrophy, laceration, ectasia, polyps, translucent vesicles, etc. The lesions are locally brittle and bleed easily when touched. In some patients, the cervix is smooth and abnormalities are found only on cytology or histology. The common clinical diagnostic methods for cervical intraepithelial neoplasia include cervical smear cytology, colposcopy, iodine test, cervical biopsy and endocervical scraping, and conical hysterectomy. Among them, conical hysterectomy is suitable for: (1) inconsistent results of cervical cytology and colposcopic biopsy, or inconsistent results of cervical cytology, colposcopy and cervical biopsy; (2) micro-infiltrating carcinoma found in cervical biopsy; (3) suspicious or cannot exclude invasive carcinoma; (4) suspicious cervical adenosquamous carcinoma; (5) abnormal or unsatisfactory pathological examination of endocervical canal scraping. 2.Treatment (1) Close observation: CINⅠ is a reversible lesion with a high rate of natural regression. Among them, 65% of lesions can regress spontaneously, 20% persist, and 15% of lesions progress. Therefore, it can be followed up regularly, closely observed, and the cervical smear can be reviewed at intervals of 3 to 6 months. However, since 10% of CINⅠ patients can develop into CINⅡ and CINⅢ, and about 0.5% can progress to invasive cancer, colposcopy-guided biopsy and endocervical scraping are needed to avoid misdiagnosis. (2) Local drug therapy: 20% to 40% silver nitrate or 50% trichloroacetaldehyde or 5% potassium dichromate or Ebony therapy can be given as local treatment. Local drug treatment has no pain, convenient treatment and other characteristics, but the need for repeated treatment, the course of treatment is longer. (3) Physiotherapy: Physiotherapy is the most commonly used clinical method, which has the advantages of no pain, quick effect, certain efficacy and low price. Commonly used physical therapy includes electrocoagulation, cryotherapy, laser therapy, microwave therapy, radiofrequency therapy, etc. Within 1 to 2 weeks after physical therapy, the vagina may discharge a large amount of watery leucorrhea due to cervical edema, accompanied by mild lumbar and abdominal cramps. It usually takes 1 to 3 months to repair the new epithelial growth of the uterine cervix. During this period, sexual intercourse and bathing should be prohibited, and antibacterial agents should be used to prevent infection. Generally, it should be reviewed once a month. (4) Surgical treatment: At present, the commonly used clinical methods are conical hysterectomy and hysterectomy. There are traditional cold knife and circular electric knife resection, both of which have an efficiency of 87% to 97% for CIN III, but this method is prone to local bleeding and cervical deformation, which can affect conception and delivery for childless people. For older patients with no childbearing requirements, hysterectomy can be performed directly. The prognosis of cervical intraepithelial neoplasia Cervical intraepithelial neoplasia can regress or reverse on its own, or remain unchanged, or progress to cervical cancer, with most CIN grade I and CIN grade II lesions regressing and returning to normal, either spontaneously or after treatment. The risk of CIN I, CIN II and CIN III developing into cervical cancer is 15%, 30% and 45% respectively, among which CIN I or CIN II can progress directly to cervical invasive cancer without going through CIN III stage. Therefore, it is very important to clarify the natural history and progression of cervical intraepithelial neoplasia for the treatment and evaluation of prognosis of patients.