Frequency of Occult High‐Grade Squamous Intraepithelial Neoplasia and Invasive Cancer within Anal Condylomata in Men Who Have Sex with Men

Human papillomavirus causes anal condylomata, high-grade anal intraepithelial neoplasia, and anal squamous cell cancer. We found high-grade intraepithelial neoplasia or squamous cell cancer in 75 (47%) of 159 HIV-seropositive men who have sex with men (MSM) and in 42 (26%) of 160 HIV-seronegative MSM with anal condylomata meriting surgery (P < .001, determined by use of the X-2 test). Anal condylomata in MSM often harbor high-grade intraepithelial neoplasia and squamous cell cancer.