Qualification of atypical squamous cells of undetermined significance in an independent laboratory: is it useful or significant?

OBJECTIVES: Correlation of cervical smears and biopsy samples emphasizes the significance of atypical squamous cells of undetermined significance as a diagnostic category.

STUDY DESIGN: A retrospective study (October 1, 1995-March 21, 1997) was performed on all Papanicolaou smears diagnosed at DIANON Systems, Inc (Stratford, Conn).

RESULTS: During this period 1551 patients with Papanicolaou smears had subsequent cervical biopsies performed within 90 days of cytologic sampling. There were 560 diagnoses of atypical squamous cells of undetermined significance. Tissue specimen results were positive in 203 cases (36.2%) and negative in 357 cases (63.8%). Of the positive biopsy results after a smear with atypical squamous cells of undetermined significance, 109 showed low-grade squamous intraepithelial lesions and 94 showed high-grade squamous intraepithelial lesions.

CONCLUSIONS: This study, the largest cytologic and histologic correlation of atypical squamous cells of undetermined significance, demonstrates that a significant percentage of smears with atypical squamous cells of undetermined significance represent squamous intraepithelial lesions and that qualification of atypical squamous cells of undetermined significance as reactive or dysplastic is useful and should serve as a guide for patient management.