The Role of Cytology and HPV Typing as a Screening Tool in Patients With Intraanal Warts

Abstract

Given that anorectal human papillomavirus (HPV) infection has been related to anal intraepithelial neoplasia (AIN) and rectal cancer, we conducted this study to evaluate the role of cytology of anal smears in the diagnosis of intraanal disease and related AIN and to correlate it to HPV genotypes. A total of 72 patients (58 males and 14 females) with perianal warts underwent anoscopy with biopsies and anal cytologic examination. Cytology was carried out for the identification of any dysplasia according to the Bethesda system. All specimens were examined with polymerase chain reaction (PCR) for HPV DNA identification. Exclusion criteria included immunosuppression and high-grade squamous intraepitheliel lesion (HGSIL) or SCC in anal specimens. Seven patients were excluded from the study. Intraanal warts were detected with anoscopy in 57 out of 65 patients, whereas histology showed HPV infection in 56 out of 65 patients and cytology was positive in 52 out of 65 low-grade squamous intraepitheliel lesion (LGSIL) patients. In 43 out of 52 positive patients, simple HPV infection was detected whereas in 9 out of 52 positive patients AIN I. HPV DNA was detected in 51 out of 65 patients, whereas 3 specimens were characterized as invalids. In the majority, HPV 6 could be identified (39/48, 81%), whereas HPV 16 was detected in 4 patients (4/48, 8.3%). One fourth of the positive patients had been infected with more than 1 HPV types (13/48, 27%). Cytology presented a sensitivity 87.5% and specificity 67% in comparison with the histology. Cytology is highly sensitive in the diagnosis of intraanal warts comparable with histopathology. The combination of the 3 examinations (anoscopy, cytology, and PCR HPV typing) improves diagnostic accuracy and offers a global picture of the anorectal HPV disease.