Cervical intraepithelial neoplasia
Cervical intraepithelial neoplasia Classification and external resources ICD-10 D06, N87 ICD-9 233.1, 622.10 MeSH D018290
Cervical intraepithelial neoplasia (CIN), also known as cervical dysplasia and cervical interstitial neoplasia, is the potentially premalignant transformation and abnormal growth (dysplasia) of squamous cells on the surface of the cervix. CIN is not cancer, and is usually curable. Most cases of CIN remain stable, or are eliminated by the host's immune system without intervention. However a small percentage of cases progress to become cervical cancer, usually cervical squamous cell carcinoma (SCC), if left untreated. The major cause of CIN is chronic infection of the cervix with the sexually transmitted human papillomavirus (HPV), especially the high-risk HPV types 16 or 18. Over 100 types of HPV have been identified. About a dozen of these types appear to cause cervical dysplasia and may lead to the development of cervical cancer. Other types cause warts.
The earliest microscopic change corresponding to CIN is dysplasia of the epithelial or surface lining of the cervix, which is essentially undetectable by the woman. Cellular changes associated with HPV infection, such as koilocytes, are also commonly seen in CIN. CIN is usually discovered by a screening test, the Papanicolaou or "Pap" smear. The purpose of this test is to detect potentially precancerous changes. Pap smear results may be reported using the Bethesda System. An abnormal Pap smear result may lead to a recommendation for colposcopy of the cervix, during which the cervix is examined under magnification. A biopsy is taken of any abnormal appearing areas. Cervical dysplasia can be diagnosed by biopsy.
Depending on several factors such as the type of HPV and the location of the infection, CIN can start in any of the three stage, and can either progress, or regress.
CIN is classified in grades:
Histology Grade Corresponding Cytology Description Image – – Normal cervical epithelium CIN 1 (Grade I) LSIL The least risky type, represents only mild dysplasia, or abnormal cell growth. It is confined to the basal 1/3 of the epithelium. This corresponds to infection with HPV, and typically will be cleared by immune response in a year or so, though can take several years to clear. CIN 2/3 HSIL Formerly subdivided into CIN2 and CIN3. CIN 2 (Grade II) Moderate dysplasia confined to the basal 2/3 of the epithelium CIN 3 (Grade III) Severe dysplasia that spans more than 2/3 of the epithelium, and may involve the full thickness. This lesion may sometimes also be referred to as cervical carcinoma in situ.
Between 250,000 and 1 million American women are diagnosed with CIN annually. Women can develop CIN at any age, however, women generally develop it between the ages of 25 to 35.
Some risk factors that have been found to be important in developing CIN are:
- Women who become infected by a "high risk" types of HPV, such as 16, 18, 31, or 45
- Women who have had multiple sexual partners
- Women who smoke
- Women who are immunodeficient
- Women who give birth before age 17
Progression and regression
However most CIN spontaneously regress. Left untreated, about 70% of CIN-1 will regress within two years, and 90% within two years.[clarification needed] About 50% of CIN 2 will regress within 2 years without treatment. Progression to cancer typically takes 15 (3 to 40) years. Also, evidence suggests that cancer can occur without first detectably progressing through these stages and that a high grade intraepithelial neoplasia can occur without first existing as a lower grade.
It is thought that the higher risk HPV infections, have the ability to inactivate tumor suppressor genes such as the p53 gene and the RB gene, thus allowing the infected cells to grow unchecked and accumulate successive mutations, eventually leading to cancer.
Treatment for higher grade CIN involves removal or destruction of the neoplastic cervical cells by cryocautery, electrocautery, laser cautery, loop electrical excision procedure (LEEP), or cervical conization. Therapeutic vaccines are also in development. The lifetime recurrence rate of CIN is about 20%, but it isn't clear what proportion of these cases are new infections rather than recurrences of the original infection.
A number of risk factors have been shown to increase a woman's likelihood of developing CIN, including poor diet, poor personal hygiene, multiple sexual partners, lack of condom use, and cigarette smoking. Using condoms increases regression of cervical dysplasia.
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Papillomavirus – Human papillomavirus Related
Vaccine Screening Colposcopy Biopsy histology Treatment History Tumors: female urogenital neoplasia (C51–C58/D25–D28, 179–184/218–221) AdnexaGlandular and epithelial/
stromal tumorSex cord-gonadal stromal
UterusCervical intraepithelial neoplasia · SCC · Glassy cell carcinoma · Villoglandular adenocarcinomaGeneral Vagina Vulva Female diseases of the pelvis and genitals (N70–N99, 614–629) InternalAdnexaVaginitis (Bacterial vaginosis, Atrophic vaginitis, Candidal vulvovaginitis) · Leukorrhea/Vaginal discharge · Hematocolpos/HydrocolposSexual dysfunction (Dyspareunia, Hypoactive sexual desire disorder, Sexual arousal disorder, Vaginismus)Other/generalPelvic inflammatory disease · Pelvic congestion syndrome External
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Look at other dictionaries:
Cervical intraepithelial neoplasia — A general term for the growth of abnormal cells on the surface of the cervix. Numbers from 1 to 3 may be used to describe how much of the cervix contains abnormal cells. Also called CIN. * * * (CIN) dysplasia of the cervical epithelium, often… … Medical dictionary
cervical intraepithelial neoplasia — (CIN) cellular changes in the cervix of the uterus preceding the invasive stages of cervical cancer. The CIN grading system distinguishes three stages: CIN 1 (mild dysplasia); CIN 2 (moderate dysplasia); and CIN 3 (severe dysplasia, carcinoma… … Medical dictionary
cervical intraepithelial neoplasia — CIN cellular changes in the cervix of the uterus preceding the invasive stages of cervical cancer. The CIN grading system distinguishes three stages: CIN 1 (mild dysplasia); CIN 2 (moderate dysplasia); and CIN 3 (severe dysplasia, carcinoma in… … The new mediacal dictionary
cervical intraepithelial neoplasia — Growth of abnormal cells on the surface of the cervix. Numbers from 1 to 3 may be used to describe how abnormal the cells are and how much of the cervical tissue is involved. Also called CIN … English dictionary of cancer terms
Неоплазия Интраэпителиальная Цервикальная (Цин) (Cervical Intraepithelial Neoplasia, Cin) — клеточные изменения, происходящие в шейке матки перед наступлением инвазивных стадий цервикального рака. Различают три стадии ЦИН: ЦИН 1 (слабая дисплазия); ЦИН 2 (умеренная дисплазия) и ЦИН 3 (сильная дисплазия, развитие карциномы). ЦИН… … Медицинские термины
Cervical squamous intraepithelial neoplasia 2 — is a condition in which moderately abnormal cells grow on the thin layer of tissue that covers the cervix. These abnormal cells are not malignant (cancerous) but may become cancer. Also called CIN 2. External links Cervical squamous… … Wikipedia
Cervical squamous intraepithelial neoplasia 1 — is a condition in which slightly abnormal cells grow on the thin layer of tissue that covers the cervix. These abnormal cells are not malignant (cancerous) but may become cancer. Also called CIN 1. External links *… … Wikipedia
cervical squamous intraepithelial neoplasia 3 — Abnormal cells are found in the cervical epithelium (the innermost lining of the cervix). These abnormal cells may become cancer and spread into nearby normal tissue. Also called stage 0 cervical carcinoma in situ and CIN 3 … English dictionary of cancer terms
cervical squamous intraepithelial neoplasia 1 — A condition in which slightly abnormal cells grow on the thin layer of tissue that covers the cervix. These abnormal cells are not malignant (cancerous) but may become cancer. Also called CIN 1 … English dictionary of cancer terms
cervical squamous intraepithelial neoplasia 2 — A condition in which moderately abnormal cells grow on the thin layer of tissue that covers the cervix. These abnormal cells are not malignant (cancerous) but may become cancer. Also called CIN 2 … English dictionary of cancer terms