BACKGROUND: Mycotic aneurysm is a rare entity with rapid progression, which can be fatal without adequate treatment. The incidence of rupture is greater than that of degenerative aneurysms and is associated with a high mortality rate. CASE REPORT: We report the case of a 58-year-old man with a known history of HIV infection with good immunovirological staging, treated squamous cell carcinoma of the anal canal a...