High grade anal dysplasia in visually normal mucosa in homosexual men: seven cases.

BACKGROUND

Anal cancer and anal human Papillomavirus (HPV) infection are increased in homosexual men.

METHODS

We screened high risk homosexual men as part of a longitudinal study examining the effect of HIV infection on the risk of development of high grade anal intraepithelial neoplasia (AIN II, III).

RESULTS

We found seven men who had histological evidence of AIN II-III with visually normal findings by anoscopy. Two men were HIV-seronegative, five were HIV-seropositive, and only one of the HIV-seropositive men had a low CD4 count < 200. Abnormal cytological results seen over follow-up periods of 3 months to 2.5 yr suggest the persistence of visually inapparent anal abnormalities. Two of the men had had small internal warts at earlier examinations, and three of the seven men subsequently developed visually abnormal anal findings. All men had HPV 16 DNA detected at some point.

CONCLUSIONS

We hypothesize that high grade anal neoplasia may develop deep in the glands and can be detected by cytology before visible lesions are detected even with the aid of a colposcope. However, the implications of finding high grade anal cytology are not known at this time. Natural history studies are ongoing.