High-resolution anoscopy: clinical features of anal intraepithelial neoplasia in HIV-positive men.

ABSTRACT

BACKGROUND: High-resolution anoscopy is increasingly advocated to screen HIV+ men who have sex with men for anal cancer and its precursor lesions, anal intraepithelial neoplasia. A systematic comparison between clinical features and the histopathology of suspect lesions is lacking. OBJECTIVE: This study aims to analyze interobserver agreement in classifying features of intra-anal lesions suspect for anal intraepithelial neoplasia and to compare these features with their histopathological outcome. DESIGN: This study is a cross-sectional survey regarding high-resolution anoscopy with images and biopsies of suspect lesions. Two dermatologists experienced in high-resolution anoscopy, blinded for histopathological outcome, independently classified the lesions on clinical features. SETTING: This investigation was conducted at the Dermatology outpatient clinic of the Academic Medical Center in Amsterdam, The Netherlands. PATIENTS Included in the study were 163 HIV+ men who have sex with men, older than 18 years, with no history of anal cancer. MAIN OUTCOME MEASURES: The primary outcomes measured were the κ-coefficient for interobserver agreement and the proportions of anal intraepithelial neoplasia per clinical feature. RESULTS: Three hundred four biopsies were taken from 163 patients. One hundred sixty-eight biopsies (55%) showed anal intraepithelial neoplasia, and 67/304 (22%) showed high-grade anal intraepithelial neoplasia. The κ-coefficient was 0.65 for condylomatous lesions, 0.14 for surface configuration, 0.54 for punctation, 0.08 for mosaicism, and 0.43 for atypical vessels. Condylomatous lesions showed high-grade anal intraepithelial neoplasia in 18% (95% CI, 11%-27%). In lesions with flat leukoplakia, punctation, and atypical vessels, high-grade anal intraepithelial neoplasia was seen in 25%, 30%, and 23%. In lesions with the combination punctation/atypical vessels and punctation/flat leukoplakia/atypical vessels, high-grade anal intraepithelial neoplasia was found in 38% and 40%. LIMITATIONS: We did not take biopsies of healthy-looking mucosa. Furthermore, the real-time description of features during high-resolution anoscopy, instead of the use of images, would improve the recognition of subtle mucosal abnormalities. CONCLUSIONS: A moderate to substantial interobserver agreement was demonstrated in recognizing condylomas, punctation, and atypical vessels. Furthermore, high-grade anal intraepithelial neoplasia is present in a high proportion of intra-anal condylomata. A combination of punctation, flat leukoplakia, and atypical vessels is the best predictor for high-grade anal intraepithelial neoplasia.