cervicovaginal cytopathology by liquiprep™ a new liquid based method in comparison with conventional pap smear

background and objective: the aim of this study was to compare the screening performance of a new modified liquid-based cytology method (liquiprep™) with conventional pap smear (cp) in a low risk population, using colposcopy followed by histology as “gold standard”. patients and methods:  this cross-sectional study was performed on random referred specimens to a general gynecological clinic in tehran, during 20 months by a split-sample method. in both cp and liquiprep™ group, all positive and 10% of negative results of smears were followed by colposcopy. a biopsy was taken whenever any atypical transformation zone seen. sensitivity, specificity, negative and positive predictive values (pv), and overall accuracy of both methods were analyzed in relation to histology. results: a total of 1265 patients were analyzed by two methods. in 158 (12.5%) of cases histological diagnosis was made. liquiprep™ samples (94.7%) were more adequate than cp (92.1%). there was not any low or high-grade squamous intraepithelial lesion (sil). atypical squamous cell of undetermined significance (asc_us) was diagnosed more with cp than with liquiprep™ (1.43% vs. 0.79%) while pathologically 60% of asc_us in liquiprep™ and 16.6% in cp had degrees of sil. the liquiprep™ had a significantly higher sensitivity (83% vs. 66%) and positive pv (83% vs. 33%) than the cp to detect sil at histology but the difference in specificity was non significant (98% vs. 86%). conclusions: this study confirms the superiority of the liquiprep™ method to detect cervical lesions in a low risk population.