Anal dysplasia in men who have sex with men.

Risk factors for anal cancer include anal intercourse and infection with multiple strains of human papillomavirus, the causative agent of anal precancerous dysplasia. Several recent studies have shown that HIV-seropositive gay men are at greater risk for anal dysplastic lesions than seronegative gay men. Moreover, the risk for detection and progression of dysplastic lesions grows as the CD4+ cell count declines. A surgeon with a practice that includes gay men referred for anorectal disease presents data regarding the high prevalence of anal dysplasia in his patients.