Rapid Prescreening as a Quality Assurance Measure in Cervical Cytology

Abstract

To assess the diagnostic validity of rapid prescreening (RPS) as a quality control method in our laboratory.All consecutive routine conventional Pap smears (n = 2,521) underwent RPS before full screening. Thirty to 60 seconds were allowed to prescreen each slide. The threshold for pathologic smear was atypical squamous cells of undetermined significance (ASCUS) or more. Smear adequacy, infections and presence of endometrial cells, if observed, were not noted on the worksheet. All smears subsequently underwent routine full screening. Results of RPS and full screening were compared.Of a total of 2,521 smears, 294 were diagnosed as abnormal (ASCUS and more) after final diagnosis. Of those, 158 were also detected on RPS. The average sensitivity of RPS was 62.2%. Twenty-five cases were detected on RPS only, among them 15 ASCUS, 8 low-grade squamous intraepithelial lesions and 2 high-grade squamous intraepithelial lesions.RPS is an efficient quality control method. It reduces false negative rate, but in our case, it affects the work flow in our laboratory, and in case of its implementation to the routine praxis the daily workload of 50 smears per day should be lowered.