[Anal intraepithelial neoplasia]

Anal intraepithelial lesions are caused by chronic infection with oncogenic types of human papillomavirus. Their incidence and prevalence are increasing, especially among patients with HIV infection. Their natural history is not well known, but high-grade intraepithelial lesions seem to have an important risk to progress to squamous cell carcinoma. Their treatment can be achieved by many ways (surgery, coagulation, imiquimod, etc.) but there is a high rate of recurrent lesions. Pretherapeutic evaluation should benefit from high-resolution anoscopy. Periodic physical examination and anal cytology may probably be interesting for screening the disease among patients with risk factors. Vaccine against oncogenic types of papillomavirus may prevent the development of anal intraepithelial neoplasia.