High-grade anal intraepithelial neoplasia: Progression to invasive cancer is not a certainty.

Background: The incidences of high-grade anal intraepithelial neoplasia (HSIL) and superficially invasive squamous cell carcinomas (SISCCA) related to human papillomavirus (HPV) have increased. These lesions can progress to invasive anal cancer. The aim of the study was to assess the clinical outcome with a special focus on the healing rate.