Atypical Squamous Cells of Undetermined Significance (ASC-US) Associated with Atrophy in Liquid-Based (Surepath) Pap Tests: Prevalence of Human Papillomavirus Infections and Follow-Up Biopsy Diagnoses
Andrew C Nelson, Tetyana N Mettler, Jana L Holler, Samy A Amirouche, 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 is still the most challenging and least reproducible diagnosis made on Pap tests. The diagnostic challenges are greatly exaggerated by the presence of atrophic changes (ATR) in the Pap test. The aim of this study was to determine the human papillomavirus (HPV) and follow-up biopsy correlates on ASC-US+ATR.
Design: We identified all cases diagnosed from 1/1/2003 to 12/31/2010 as ASC-US with concomitant atrophic changes (ASC-US+ATR) 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+) was compared statistically to those of all other cases of ASC-diagnosed within the same interval.
Results: Of the 23077 cases diagnosed as ASC-US during the study interval, 284 (1.23%) were associated with ATR.
|AGE (MEAN+/-SD)||ALL HPV TYPES||HR-HPV TYPES||HPV TYPES 16/18||BIOPSY RATE||CIN1+||CIN2+|
|ALL ASC-US (N=23077)||36.3+/-13.2||8937 (38.7%)||4277 (18.5%)||1993 (8.6%)||4241 (18.4%)||1845 (8%)||581 (2.52%)|
|ASC-US+ATR (N=284)||59.4+/-10.4||39 (13.7%)||17 (6%)||3 (1.1%)||22 (7.8%)||5 (1.8%)||2 (0.7%)|
|ASC-US+ATR VS. ALL ASC-US %CHANGE||-125%||-67.7%||-87.8%||-57.9%||-106.2%||-101.8%|
|ASC-US+ATR VS. ALL ASC-US p VALUE||<0.0001||<0.0001||<0.0001||<0.0001||<0.0001||<0.0001||NS (0.053)|