[445] Reflex HPV Testing in Vaginal Smears

CM Mitchell, CM Bradford, NR Wadhwani, S Mehrotra, GA Barkan, U Kapur. Loyola University Medical Center, Maywood, IL

Background: High-risk human papillomavirus (hrHPV) testing for triage of Papanicolaou smears with an interpretation of atypical squamous cells of undetermined significance (ASCUS) is well established. Current management recommendations for ASCUS are: hrHPV testing, repeat cervical cytology, or colposcopy; although hrHPV testing is preferred. These recommendations are for cervical specimens; the original studies excluded women with a prior hysterectomy. In clinical practice, reflex hrHPV testing is performed on vaginal smears with ASCUS. Few studies have assessed hrHPV testing in vaginal smears. The purpose of this study is to see if hrHPV triage in vaginal smears is informative.
Design: A retrospective review was performed on vaginal smears with an interpretation of ASCUS and reflex hrHPV testing collected from January 2006 to December 2007 and correlated with follow-up cytology and histology.
Results: An interpretation of ASCUS was rendered on 96 of 2949 vaginal smears. The ASCUS rate was 3.2% compared to an overall ASCUS rate of 9.8% at the same institution in 2007. HPV reflex testing was performed on 56/96. There were 47 hrHPV negative cases and 9 hrHPV positive cases for an overall ASCUS hrHPV positive rate of 16%. Follow-up vaginal smears were available in 44 patients and a follow-up biopsy was available in one patient.

Vaginal Smear Follow-up
ASCUS HPV -25573757 (21-76)
ASCUS HPV +412750 (39-63)

A squamous intraepithelial lesion (SIL) was identified in nine patients; two from the hrHPV positive group and seven from the hrHPV negative group. All of the SIL was interpreted as low-grade, except for one patient in the hrHPV positive group who had a high-grade squamous intraepithelial lesion. This patient had a hysterectomy for severe cervical dysplasia and had recurrent vulvar squamous dysplasia. There was no significant difference in the diagnosis of SIL between the hrHPV positive group and the hrHPV negative group (p=0.67).
Conclusions: Although this study had a small sample size, the observed 16% hrHPV positivity rate is well below the reported rate in cervical specimens of approximately 40%. The low prevalence of hrHVP in vaginal specimens may explain the low ASCUS rate. There was no significant difference in follow-up between hrHPV positive and hrHPV negative ASCUS vaginal smears. These results suggest that hrHPV triage does not provide additional information. Perhaps a different testing algorithm with increased follow-up may be considered in place of hrHPV triage in vaginal smears with ASCUS.
Category: Cytopathology

Tuesday, March 23, 2010 9:30 AM

Poster Session III # 85, Tuesday Morning


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