High resolution anoscopy findings for men who have sex with men: inaccuracy of anal cytology as a predictor of histologic high-grade anal intraepithelial neoplasia and the impact of HIV serostatus.

We compared the pathological diagnoses obtained by anal Papanicolaou (Pap) smear with those obtained by anal biopsy or by surgical excision for 153 men who have sex with men (MSM). Analysis of these paired specimens showed that anal Pap smears were an inaccurate predictor of high-grade anal dysplasia, regardless of human immunodeficiency virus (HIV) serostatus. The presence of any abnormal anal cytological finding indicates a potential for high-grade dysplasia on histological examination of MSM.