Cytology as a screening tool for anal squamous intraepithelial lesion for HIV positive men: 10-year experience in an inner city hospital

IntroductionHuman papillomavirus (HPV) and anal carcinoma are prevalent in high-risk patients including human immunodeficiency virus (HIV)-positive patients. There are currently no clear guidelines for screening, however. We assessed anal cytology specimens and HPV testing at an inner-city hospital by correlating anal cytology with anal biopsy (bx), and evaluated if results differed with traditional proctoscopy (TP) or high-resolution anoscopy (HRA).Materials and methods209 anal cytology and subsequent biopsies taken during the period 2003-2014 from 152 male patients were reviewed. Demographic data for age, sex, HIV, HPV, cytology, histology, and the method of biopsy were analyzed.ResultsAll specimens were followed by a biopsy within a period of 6 months. Ninety-seven percent of patients were HIV-positive and 43% had AIDS. Lesions most diagnosed on cytology were low-grade squamous intraepithelial lesion (LSIL) (52%) and atypical squamous cells of undetermined significance (ASC-US) (21.5%). Lesions most diagnosed on bx were anal intraepithelial neoplasia (AIN) grade 2-3 (52%) and AIN grade 1 (37%). Almost all ASC-US cases tested for HPV were positive (97%). There was cytology histology correlation in 48% of LSIL and 83% of high-grade squamous intraepithelial lesions. Anal cytology had 97% sensitivity in detecting AIN and carcinoma and a positive predictive value of 96%. There was no difference in rate of detection of AIN 1and AIN 2-3 on bx using TP versus HRA.ConclusionScreening in high-risk patients detected almost all high- and low-grade squamous intraepithelial lesions, however, anal cytology alone could not predict the degree of dysplasia. It may be prudent to perform anal bx in all atypical anal cytology. Clear guidelines are needed for screening of a high risk population.