[409] Atypical Squamous Cells of Undetermined Significance (ASC-US) Associated with Atypical Repair in Liquid-Based (Surepath) Pap Tests: Prevalence of Human Papillomavirus Infections and Follow-Up Biopsy Diagnoses

Andrew C Nelson, Arbaz Samad, Samy A Amirouche, Jana L Holler, Stefan E Pambuccian. University of Minnesota Medical Center, Fairview, Minneapolis, MN

Background: Despite its use for more than two decades and the clearly formulated Bethesda system diagnostic criteria, the diagnosis of atypical squamous cells of undetermined significance (ASC-US) is still the most challenging and least reproducible diagnosis made on Pap tests. ASC-US associated with atypical reparative changes (ASC-US+ATYREP) is one of the subtypes of ASC-US recognized by the Bethesda System. Studies that have addressed the question of the significance of ASC-US+ATYREP have arrived to conflicting results, some authors even arguing against retaining this diagnostic category under ASC-US. The aim of this study was to determine the human papillomavirus (HPV) and follow-up biopsy correlates on ASC-US+ATR in an attempt to shed further light on this issue.
Design: We identified all cases diagnosed from 1/1/2003 to 12/31/2010 as ASC-US with atypical repair (ASC-US+ATYREP) that had reflex HPV testing performed by a PCR-based method using MY09/11 consensus primers and typing by RFLP. All cases were diagnosed by 2001 Bethesda System criteria on Surepath Pap tests. The prevalence of any HPV type, high-risk HPV types (HR-HPV) and HPV16/18 and the frequency of abnormal follow-up biopsies diagnosed as CIN1 and above (CIN1+) and CIN2 and above (CIN2+) in women with ASC-ATYREP was compared statistically to those of all other cases of ASC-US diagnosed within the same time interval.
Results: Of the 23077 cases diagnosed as ASC-US during the study interval, 188 (0.81%) were associated with ATYREP.

ALL ASC-US (N=23077)36.3±13.28937 (38.7%)4277 (18.5%)1993 (8.6%)4241 (18.4%)1845 (8%)581 (2.52%)
ASC-US+ATYREP (N=188)38.9±13.646 (24.5%)23 (12.2%)19 (10.1%)29 (15.4%)10 (5.3%)3 (1.6%)

Women with ASC-US+ATYREP were slightly older than other women with ASC-US, which most likely contributed to their lower HPV rates.
Conclusions: In our institution, ASC-US+ATYREP is a rare diagnosis and contributes to only a small fraction of ASC-US diagnoses.
We found lower overall HPV rates but similar HPV16/18 and abnormal follow-up biopsy rates in women with ASC-US-ATYREP compared to all ASC-US cases. Our results suggest retaining this diagnostic category under ASC-US.
Category: Cytopathology

Tuesday, March 20, 2012 9:30 AM

Poster Session III # 50, Tuesday Morning


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