The significance of ASC-H and LSIL dual interpretation with risk stratification: one institution experience.

Introduction The 2014 Bethesda System categorizes squamous lesions as low-grade squamous intraepithelial lesions (LSIL) and high-grade squamous intraepithelial lesions (HSIL). It also includes intermediate morphologic terminology, such as atypical squamous cells of undetermined significance (ASC-US) and atypical squamous cells, cannot rule out a high grade squamous intraepithelial lesion (ASC-H). Consensus is lacking if when ASC-H is present in an unequivocal LSIL (LSIL + ASC-H) versus ASC-H alone predicts a neoplasm with a different biologic behavior and which is its association with high-risk human papillomavirus (HPV). Materials and methods We reviewed the Columbia University Medical Center Pathology department patient’s database from October 2012 through December 2014 and found 2498 cytology samples of LSIL, ASC-H, HSIL, and LSIL + ASC-H with both follow-up histologic samples and HPV tests by Roche cobas. Our objective was to identify, if any, differences in biologic behavior and HPV status present in LSIL + ASC-H compared with ASC-H and other lesions. Results CIN2+ was documented in tissue examination in 102 from 311 LSIL + ASC-H (32.8%), 101 from 219 ASC-H (46.1%), 252 from 326 HSIL+ (77.3%), and 150 from 1642 LSIL (9.08%). HPV distribution shows significant differences between all diagnostic categories. Conclusions LSIL + ASC-H appears to have a distinctive HPV distribution pattern that clearly differs from ASC-H and LSIL and approaches HSIL; however, the predictive value for CIN2+ appears higher for ASC-H than LSIL + ASC-H. Our literature review identified conflicting findings, probably suggesting a lack of reproducibility in cytologic criteria and the need for consistent inclusion of ASC-H and LSIL when both are present.