Variance in the interpretation of cervical biopsy specimens obtained for atypical squamous cells of undetermined significance

We sought to determine whether the variability in dysplasia rates in cases of atypical squamous cells of undetermined significance (ASCUS) reflects va riability in interpretation of cervical biopsy specimens. In phase 1, 124 b iopsy specimens obtained because of a cytologic diagnosis of ASCUS were rev iewed independently by 5 experienced pathologists. Diagnostic choices were normal, squamous metaplasia, reactive, indeterminate, low-grade squamous in traepithelial lesion (LSIL), and high-grade squamous intraepithelial lesion (HSIL). The rate of dysplasia ranged from 23% to 51%. All pathologists agr eed in 28% of cases. In 52% of cases, the diagnoses ranged from benign to d ysplasia. The overall interobserver agreement was pool: In phase 2, 60 cerv ical biopsy specimens (21 obtained for ASCUS, 22 for LSIL, and 17 for HSIL) were evaluated using the same diagnostic choices. Agreement was better in biopsies performed for HSIL and LSIL compared to those for ASCUS. Intraobse rver reproducibility in the interpretation of biopsies performed for ASCUS ranged fr om poor to excellent We conclude that variability in the interpre tation of biopsy specimens plays an important role in the differences in ra tes of dysplasia reported for the follow-up of ASCUS.