anal intraepithelial neoplasia


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Related to anal intraepithelial neoplasia: Endometrial Intraepithelial Neoplasia, Prostatic intraepithelial neoplasia, Vulvar intraepithelial neoplasia

anal intraepithelial neoplasia

A carcinoma in situ of the anorectal mucosa that is embryologically, histologically, and pathologically analogous to cervical intraepithelial neoplasia, which is linked to HPV infection and divided into low-grade (LG-AIN) and high-grade (HG-AIN) tumours, the latter of which is associated with aggressive squamous cell carcinoma.

Risk factors
Anal HPV infections, receptive anal intercourse, HIV infection and decreased CD4-+ve T cells.
 
HPV types
6/11, 31/33/35 and 16/18.

anal intraepithelial neoplasia

Abbreviation: AIN
A precancerous change in the squamous cells of the anus that may eventually develop into anorectal cancer. It is similar to cervical intraepithelial neoplasia in that it is a premalignant lesion that arises in squamous cells, is found primarily in sexually active people, and is associated with human papillomavirus and HIV.
Synonym: anal dysplasia; anal squamous intraepithelial lesion
See also: neoplasia
References in periodicals archive ?
Several single-center studies in the combination antiretroviral therapy era have assessed the power of abnormal anal cytology to predict anal intraepithelial neoplasia (AIN) or other outcomes (Table 2).
Anal squamous Intraepithelial lesions (SIL) and anal Intraepithelial neoplasia (AIN) are names for the lesions caused by dysplasia.
Conventionally, lesions involving the former have been termed dysplasia, in situ carcinoma, or anal intraepithelial neoplasia, whereas lesions involving the skin, Bowen disease.
A recent study of anal intraepithelial neoplasia indicated that, like in the uterine cervix, both markers offer utility to distinguish low-grade SIL from high-grade SIL.
42) Detection of multiple HPV types is associated with both anal intraepithelial neoplasia and progression to higher grade lesions over time.
A 2009 meta-analysis of 93 studies from four continents reckoned HPV rates in people with vulvar, vaginal, or anal intraepithelial neoplasia grades 1 to 3 and carcinoma.
In December 2010, GARDASIL was approved for the prevention of anal cancer caused by HPV types 16 and 18 and for the prevention of anal intraepithelial neoplasia (AIN) grades 1, 2 and 3 (anal dysplasias and precancerous lesions) caused by HPV types 6, 11, 16 and 18, in males and females 9 through 26 years of age, based on a substudy within this Phase III study.
Food and Drug Administration (FDA) has approved GARDASIL([R]) [Human Papillomavirus Quadrivalent (Types 6, 11, 16, and 18) Vaccine, Recombinant] for the prevention of anal cancer caused by human papillomavirus (HPV) types 16 and 18 and for the prevention of anal intraepithelial neoplasia (AIN) grades 1, 2 and 3 (anal dysplasias and precancerous lesions) caused by HPV types 6, 11, 16 and 18, in males and females 9 through 26 years of age.