Increased rate of atypical squamous cells of undetermined significance and declining high-risk human papillomavirus rates following implementation of ThinPrep Imaging System are associated with increased nuclear chromasia

Imager stain implementation, required for the ThinPrep Imaging System, led to significant increase in ASCUS rates while the hrHPV-positive rate declined. Cytopathologists will need to recalibrate thresholds for an ASCUS diagnosis when interpreting Imager-stained slides. In particular, nuclear hyperchromasia in squamous metaplastic cells should not be overdiagnosed as ASCUS.