Squamous carcinoma of the anus in young homosexual men with T helper cell depletion.

Two cases of squamous carcinoma of the anus in white homosexual men aged 36 and 47 years are reported, each with a short history of rapidly enlarging perianal lesions. Immunological studies showed that both men had pronounced T helper lymphocyte depletion, and antibody to human T cell lymphotropic virus type III (HTLV-III) was detected in both patients. In addition one patient had a long history of wart virus infection of the anal canal. The diminished cellular immunity associated with HTLV-III may have been responsible for the development of the squamous carcinoma, either directly or by its association with human papilloma virus infection.