SQUAMOUS-CELL CARCINOMA OF THE ANUS AND RECTUM IN HOMOSEXUAL MEN - CTFINDINGS

Objective: Homosexual men are at risk for a variety of infectious and neoplastic diseases of the anus and rectum, many of which have been re ported in the radiologic literature. The purpose of this study was to describe the CT findings in homosexual men with squamous cell carcinom a of the anus and rectum, a topic that has received little attention. Materials and Methods: Computed tomography examinations of the abdomen and pelvis of nine homosexual men with squamous cell carcinoma of the anus and rectum were reviewed retrospectively. Six HIV-positive men w ere 28-44 years old (average, 37 years). Three HIV-negative men were 4 7-61 years old (average, 54 years). Results: In six of the nine patien ts, CT showed a mass involving the anal canal. In five of these six pa tients, the tumor extended caudad to involve perianal fat and skin (on e patient), cephalad to involve the rectum and perirectal fat (two pat ients), or both (two patients). In three of the nine patients, the ana l canal did not appear to be involved by the tumor; CT showed circumfe rential rectal wall thickening (one patient), an excavated eccentric r ectal tumor (one patient), or a cystic extramucosal rectal mass (one p atient). Computed tomography evidence of noncontiguous metastasis was limited to inguinal and iliac lymph node enlargement in two of the nin e patients. Conclusion: Because CT findings are varied and nonspecific , squamous cell carcinoma should be included in the differential diagn osis of anorectal lesions in homosexual men.