Off-label high-risk HPV DNA testing of vaginal ASC-US and LSIL cytologic abnormalities at Parkland Hospital

Objective.: To investigate the frequency and outcome of high-risk human papillomavirus (HPV) DNA testing of atypical squamous cell of unknown significance (ASC-US) and low-grade squamous intraepithelial lesion (LSIL) vaginal ThinPrep Pap tests (TPPTs). Methods.: Atypical squamous cell of unknown significance and LSIL vaginal TPPTs (from women without a cervix) from 2005 to 2008 were identified retrospectively. The frequency of HPV testing in response to these cytologic abnormalities and results of testing were determined and compared with cervical TPPTs. The frequency and results of subsequent vaginal biopsies were reviewed. Results.: Of the ASC-US vaginal TPPTs, 76.5% (270/353) underwent HPV testing, with 31.9% (86/270) positive. Atypical squamous cell of unknown significance cervical TPPTs underwent HPV testing less often (69.5%, 7,155/10,297) but were more commonly HPV-positive (49.7%, 3,558/7,155). Similarly, the majority of LSIL vaginal TPPTs (59.2%, 202/341) underwent HPV testing, with 66% (133/202) testing positive. This compares with only 11.0% (1,092/9,947) of cervical LSIL TPPTs undergoing HPV testing, with 73.2% (799/1,092) positive. The increased rates of HPV test performance and lower rates of HPV positivity in vaginal ASC-US and LSIL TPPTs compared with similarly abnormal cervical TPPTs were statistically significant (p <.05) by χ analysis. Histologic evaluation was more common after HPV-positive ASC-US or LSIL vaginal TPPTs compared with HPV-negative results. Most high-grade vaginal neoplasias were diagnosed subsequent to a positive HPV result. Conclusions.: Human papillomavirus testing of ASC-US and LSIL vaginal TPPTs is common; lower rates of HPV positivity were found in vaginal versus cervical ASC-US and LSIL TPPTs. The majority of high-grade vaginal neoplasias were diagnosed subsequent to positive HPV testing. Evidence-based guidelines for the use of HPV testing for the management of vaginal cytologic abnormalities are needed.