Background: Both anal squamous cell cancer and human papilloma virus (HPV) are increased in homosexual men. This study evaluates histology of internal anal abnormalities in a high-risk population of human immunodeficiency virus (HIV) seropositive and seronegative homosexual men.
Methods: Ninety men with abnormalities of the internal anal canal (referred from a cross-sectional study of 512 homosexual men) were evaluated by anoscopy, anal cytology, and directed biopsy. CD4 cell counts from blood and HPV types from anal tissue were also obtained.
Results: Seventy-eight (86%) men had HPV-associated abnormalities: discrete warts in 39 (43%), a wart ring in 23 (26%), and flat white epithelium in 18 (20%). Dysplasia was detected by cytology in 36% and by biopsy in 92% (27% high grade). High-grade dysplasia was equally common in HIV-seropositive and -seronegative men. The morphology of anal lesions did not predict the presence of dysplasia. Both high- and low-risk HPV types were common in many of the biopsy specimens.
Conclusions: Anal dysplasia is common in biopsy specimens from homosexual men with visible HPV-associated internal anal abnormalities. Natural history studies are needed to determine the clinical significance of anal dysplasia, rates of progression to cancer, and the role of screening and therapy.