Cervical intraepithelial neoplasia 3059242 225767532 2008-07-15T08:55:04Z Zodon 6424546 /* Treatment */ summarized therapeutic vaccines with wikilink __NOTOC__ '''Cervical intraepithelial neoplasia''', or '''CIN''', also known as cervical dysplasia, is the abnormal growth of potentially [[precancerous]] [[Cell (biology)|cells]] in the [[cervix]]. 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, or SCC.<ref name="Agorastos">{{cite journal |author=Agorastos T, Miliaras D, Lambropoulos A, Chrisafi S, Kotsis A, Manthos A, Bontis J |title=Detection and typing of human papillomavirus DNA in uterine cervices with coexistent grade I and grade III intraepithelial neoplasia: biologic progression or independent lesions? |journal=Eur J Obstet Gynecol Reprod Biol |volume=121 |issue=1 |pages=99–103 |year=2005 |pmid=15949888 |doi=10.1016/j.ejogrb.2004.11.024}}</ref> The major cause of CIN is infection with the sexually transmitted [[human papillomavirus]] (HPV), usually the high-risk HPV types 16 or 18. The earliest microscopic change corresponding to CIN is [[dysplasia]] of the [[epithelium|epithelial]] or surface lining of the [[cervix]], which is essentially undetectable by the woman. Cellular changes associated with HPV infection, such as [[koilocyte]]s, are also commonly seen in CIN. It is usually discovered by a screening test, the [[pap smear|Papanicolaou or "pap" smear]]. The purpose of this test is to detect the changes early, while it has not yet progressed to invasive carcinoma, and is easier to cure. ==Grades== CIN is classified in grades: * '''CIN1''' (Grade I), the least risky type, represents only mild [[dysplasia]], or abnormal cell growth<ref name="Agorastos"/> and corresponds to a '''low grade squamous intraepithelial lesion''' (LGSIL). <ref name="Park">{{cite journal |author=Park J, Sun D, Genest D, Trivijitsilp P, Suh I, Crum C |title=Coexistence of low and high grade squamous intraepithelial lesions of the cervix: morphologic progression or multiple papillomaviruses? |journal=Gynecol Oncol |volume=70 |issue=3 |pages=386–91 |year=1998 |pmid=9790792 |doi=10.1006/gyno.1998.5100}} </ref>. 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. * '''CIN2/3''' correspond to '''high grade squamous intraepithelial lesions''' (HSIL). <ref name="Park"/> Sometimes this is further divided: ** '''CIN2''' (Grade II): Moderate dysplasia confined to the basal 2/3 of the epithelium ** '''CIN3''' (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]]. <br/> <gallery> Image:Cervical intraepithelial neoplasia (1) normal squamous epithelium.jpg|Normal cervical epithelium (H&E stain). Image:Cervical intraepithelial neoplasia (2) koilocytosis.jpg|Grade I CIN. Image:Cervical intraepithelial neoplasia (3) CIN2.jpg|Grade II CIN. Image:Cervical intraepithelial neoplasia (5) CIN3.jpg|Grade III CIN. </gallery> ==Progression== Cases of CIN are thought by some to progress through these stages toward cancer in a linear fashion.<ref name="Agorastos"/><ref>{{cite journal |author=Hillemanns P, Wang X, Staehle S, Michels W, Dannecker C |title=Evaluation of different treatment modalities for vulvar intraepithelial neoplasia (VIN): CO(2) laser vaporization, photodynamic therapy, excision and vulvectomy |journal=Gynecol Oncol |volume=100 |issue=2 |pages=271–5 |year=2006 |pmid=16169064 |doi=10.1016/j.ygyno.2005.08.012}}</ref><ref>{{cite journal |author=Rapp L, Chen J |title=The papillomavirus E6 proteins |journal=Biochim Biophys Acta |volume=1378 |issue=1 |pages=F1–19 |year=1998 |pmid=9739758}}</ref> However most CIN spontaneously regress. 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.<ref name="Agorastos"/><ref>{{cite journal |author=Monnier-Benoit S, Dalstein V, Riethmuller D, Lalaoui N, Mougin C, Prétet J |title=Dynamics of HPV16 DNA load reflect the natural history of cervical HPV-associated lesions | journal=J Clin Virol |volume=35 |issue=3 |pages=270–7 |year=2006 |pmid=16214397 |doi=10.1016/j.jcv.2005.09.001}}</ref> ==Treatment== In many cases, CIN will regress without treatment. A [[Diet (nutrition)|diet]] rich in [[fruit]]s and [[vegetable]]s, [[Tobacco smoking|smoking]] avoidance and [[condom]] use [[Human papillomavirus#Cervical cancer detection and prevention | increase regression]] of cervical dysplasia. Cervical dysplasia is curable, although the lifetime recurrence rate is 20%. Methods used to treat cervical dysplasia require destruction of the surface cells of the cervix. These methods include [[cryocautery]], [[electrocautery]], [[Cauterization|laser cautery]], [[Loop electrical excision procedure|LEEP]], and [[cervical conization]]. Therapeutic [[HPV vaccine|vaccines]] are also in development. ==See also== * [[Cervical cancer]] * [[Human papillomavirus]] ==References== {{Reflist}} [[Category:Types of cancer]] [[Category:Gynecology]] [[Category:Papillomavirus]] [[bg:Цервикална интраепителна неоплазия]] [[es:Neoplasia cervical intraepitelial]] [[sl:Cervikalna intraepitelijska neoplazija]] [[sv:Cervikal intraepitelial neoplasi]] [[vi:Tân sinh trong biểu mô cổ tử cung]]