The Significance of ASCUS-Equivocal High Risk HPV DNA Tests in ThinPrep Specimens: A Cytologic/Histologic Review of 315 Cases.
Kim HooKim, Brian Smola, Duane Newton, Richard Lieberman, Stewart Knoepp. University of Michigan, Ann Arbor
Background: High risk HPV testing (hrHPVT) improves early detection of precancerous cervical lesions, particularly in patients 30 years or older with normal Pap tests and in patients showing Atypical Squamous Cells of Undetermined Significance (ASCUS) on Pap. Up to 11.4% of the latter are associated with “equivocal” hrHPVTs, for which the current recommendation is repeat testing. To date, no study has adequately analyzed the clinicopathologic significance of “equivocal” hrHPVTs associated with ASCUS cytology in ThinPrep specimens.
Design: All ThinPrep Pap tests diagnosed as ASCUS over a 5-year period were reviewed, and specimens with a corresponding hrHPVT (Hybrid Capture II) and cervical biopsy performed within 2 years were selected. Resulting cases were grouped into three cohorts based on hrHPVT: positive, negative, or equivocal. Equivocal hrHPVT was defined as any positive test below 5 relative light units (RLU/CO). Follow-up histology was correlated with corresponding hrHPVT results. Cases of high-grade dysplasia were reviewed by 2 pathologists.
Results: 9,012 of 274,941 ThinPrep Pap tests were diagnosed as ASCUS, and of these, 7,050 had associated hrHPVTs. HrHPVTs were positive in 2449 (34.7%) cases, negative in 4170 (59.2%) cases, and equivocal in 431 (6.1%) cases. Follow-up histology was available on 945 specimens, of which we selected all 69 equivocal cases, and sequentially 150 positive, and 96 negative cases. High-grade dysplasia was seen in 20.3% of equivocal (CIN II 5.8%, CIN III 14.5%) and 16.5% (CIN II 12%, CIN III 4.7%) of positive hrHPVTs. Comparatively, only 5.2% of negative hrHPVTs showed high-grade dysplasia (CIN II 4.2%, CIN III 1%) on follow-up.
Conclusions: ASCUS with equivocal hrHPVT on ThinPrep specimens correlated with more frequent high-grade dysplasia on follow-up cervical histology than did unequivocal positive hrHPVTs, and moreover correlated with more severe dysplasia (i.e., more CIN 3). Therefore, ASCUS-equivocal hrHPVTs should not be repeated as currently recommended but managed similarly to ASCUS-positive hrHPVT. These tests may indicate a higher risk of dysplasia than those associated with unequivocal positive hrHPVTs.
Category: Gynecologic & Obstetrics
Monday, February 28, 2011 1:30 PM
Platform Session: Section C, Monday Afternoon