Squamous cell carcinoma of anus or anal canal

A squamous cell carcinoma (SCC) arising from the anal canal up to the junction with the anal margin (perianal, hair-bearing skin). Human papillomavirus is detected in the majority of cases. Homosexual HIV-positive men have an increased risk of developing anal squamous cell carcinoma in comparison to the general male population. The prognosis is generally better for anal margin SCC than for anal canal SCC. The former are classified with skin tumours.