Atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion: review of ancillary testing modalities and implications for follow-up.

OBJECTIVE: To review the cytology category atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H), with human papillomavirus (HPV) and other ancillary testing results and according to age group. METHODS: A literature search was performed on the ASC-H category, and studies analyzing ASC-H according to ancillary testing modalities or patient age groups during the past 4 years were emphasized. RESULTS: The ASC-H category accounts for less than 1% of cytology reports, and 33% to 84% will test positive for oncogenic HPV. The number of patients with cervical intraepithelial neoplasia 2/3 and cancer on biopsy is quite variable, from about 12% to more than 70%, averaging about 40%. The variation reflects patient population as well as local laboratory practices, but older subgroups are more likely to have negative HPV results and negative follow-up. Both the sensitivity of HPV testing for cervical intraepithelial neoplasia 2/3 detection and the negative predictive value for a patient with ASC-H and negative HPV testing average more than 95%. Additional studies evaluating other types of ancillary testing for the ASC-H category are needed. CONCLUSIONS: Atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion, is an uncommon cytology result, and HPV testing results and biopsy follow-up show variation according to patient age group and local laboratory practices. A negative HPV result in ASC-H offers a high negative predictive value and could be considered as a management strategy in mature women as well as women 30 years and older receiving combined cytology and HPV screening.