Analyses of atypical squamous cells refined by the 2001 Bethesda System: the distribution and clinical significance of follow-up management.

This study was conducted to analyze the clinical significance of follow-up diagnostic methods of atypical squamous cells (ASC) (the 2001 Bethesda System) cases according to age. A computerized search of the cytology database was performed to retrieve all cases diagnosed as ASC from 2001 to 2003. The pathologic reports for all follow-up diagnoses were reviewed. We divided the patients into two groups according to their age, younger than 50 years of age and 50 years and older, and follow-up diagnoses were compared between the two groups. ASC was identified in 1035 (2.0%) of 49,882 women screened, and a total of 914 patients were eligible. In atypical squamous cells of undetermined significance (ASC-US) cases, colposcopically directed biopsy showed CIN I (CIN is cervical intraepithelial neoplasia) or higher grade lesions in 34.9% of cases younger than 50 years of age and in 17.4% of cases 50 years and older (P= 0.000). However, repeat Pap smears and human papillomavirus DNA testing showed no differences between the two groups. In contrast, the three methods did not exhibit significant difference between the two groups in patients with atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H) (P= 0.743). Colposcopically directed biopsy for the ASC-US was more useful in patients younger than 50 years of age than in those who were 50 years and older. It is suggested that age should be considered in deciding follow-up diagnostic methods in patients with ASC-US.