Bethesda 2001 implementation and reporting rates: 2003 practices of participants in the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology

The 2001 Bethesda System for the reporting of cervical cytology specimens and the use of new liquid-based and human papillomavirus testing technologies have led to changes in cervical cytology reporting practices. To analyze current laboratory reporting practices using Bethesda 2001 terminology and to compare results with previous survey data from 1996. Questionnaire survey mailed to 1751 laboratories in mid-2003. Laboratories enrolled in the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology. Of the 759 responding laboratories, most (85.5%) had implemented Bethesda 2001 terminology, and the majority had adopted major changes, such as elimination of the benign cellular changes category and the satisfactory but limited category. The median reporting rate for low-grade squamous intraepithelial lesion was 2.1%, compared to a 1996 median rate of 1.6%, but the increase was confined to liquid-based preparations. Reporting rates for high-grade squamous intraepithelial lesion (median, 0.5%) and atypical squamous cells (ASC) had changed little. Most ASC cases were subclassified as "undetermined significance" (median, 3.9%) with ASC, cannot exclude high-grade SIL accounting for a minority (median, 0.2%). The median ratio of ASC to squamous intraepithelial lesions and carcinomas (SIL+) was 1.4 and was lower than the 1996 median ratio of 2.0. Median reporting rates for squamous abnormalities for 2002 were noted to be significantly higher for liquid-based preparations than for conventional smears, while median ASC/SIL+ ratios were lower. Most laboratories offer human papillomavirus testing, but almost half (47%) of laboratories do not know the percentage of positive testing results in patients with ASC. Most laboratories have implemented Bethesda 2001 terminology. New criteria and liquid-based methods have led to an increase in low-grade squamous intraepithelial lesion reporting rates and a decrease in ASC/ SIL+ ratios when compared with 1996 data. Liquid-based preparations have higher median squamous intraepithelial lesion rates and lower ASC/SIL+ ratios than conventional smears.