Squamous cells are cells that make up part of the outer layer of skin.
This page is intended to provide information about anal cancer and its precursors, high grade and low grade anal squamous intraepithelial lesions(HSIL and LSIL respectively). You will also find information on human papilloma virus (HPV), the cause of over 90% of anal cancers. (HPV is also responsible for over 95% of cervical cancers, as well as genital and anal warts.)
The good news is only a fraction of people with anal HPV infection will develop a lasting case of HSIL or LSIL, and even fewer will progress into anal cancer.
We also have a national list of providers who have been trained in HRA (high resolution anoscopy), the technique currently thought to be the best for detecting precancerous lesions and anal cancer.