HPV Results on Unsatisfactory Gynecologic Pap Specimens
V Ko, KC O'Reilly, A Ly, CA Temmins, K CS. Stanford University, Stanford, CA; Hoag Memorial Hospital Presbyterian, Newport Beach, CA
Background: Unsatisfactory pap smears are a common problem in gynecologic cytology. Although Human Papilloma Virus (HPV) testing is requested on these specimens, the validity of HPV results from unsatisfactory pap smears is not well studied.
Design: A search for all unsatisfactory pap smears (ThinPrep and SurePath) with concurrent HPV tests (Digene HybridCapture II) during a 1 year (2006) period was performed utilizing the pathology database system at Stanford Hospitals & Clinics. The cause of the unsatisfactory specimen and the HPV results were recorded. The patients' pap smear and HPV test results for up to 1 year before and after the unsatisfactory specimen were noted. In addition, the HPV+ rate was determined for 1 year of NILM and abnormal paps.
Results: 166 unsatisfactory pap smears with HPV tests were found, with 11 positive (6.6%), 152 negative (91.5%) and 3 equivocal (1.8%) cases. 27 cases had HPV testing within one year of the unsatisfactory specimen. 4/27 cases had discordant results: 1) equivocal to positive (106 days), 2) negative to equivocal (115 days), 3) positive to equivocal (365 days), and 4) negative to positive (30 days). All four cases were unsatisfactory due to scant cellularity, one of which also had obscuring lubricant. There were also 35 pap tests within 1 year of the original specimen: 34 NILM following a negative HPV, and 1 LSIL following a positive HPV. Overall, there was 1 definite false negative HPV result out of the 62 cases (1.6%) with prior or subsequent HPV or pap tests. The false negative case was negative due to scant cellularity. The HPV positive rate for unsatisfactory specimens was compared to baseline HPV rates by diagnosis, showing similarity to the NILM HPV rate.
|DIAGNOSIS||TOTAL # CASES||HPV+ (%)|
|REASON FOR UNSATISFACTORY:|
|Insufficient squamous epithelial component||5||20|
Conclusions: There are few studies in the literature examining whether unsatisfactory pap smears provide enough material for a valid HPV test result. This study provides preliminary evidence that these specimens provide reliable HPV results with a low false negative rate.
Wednesday, March 11, 2009 9:30 AM
Poster Session V # 31, Wednesday Morning