Clinical importance of “low-grade squamous intraepithelial lesion, cannot exclude high-grade squamous intraepithelial lesion (LSIL-H)” terminology for cervical smears: 5-year analysis of the positive predictive value of LSIL-H compared with ASC-H, LSI

ObjectiveWe compared follow-up biopsy findings and positive predictive values (PPVs) for cervical intraepithelial neoplasia 2 or worse (CIN 2+) in cases that were cytologically interpreted as low-grade squamous intraepithelial lesions (LSIL); high-grade squamous intraepithelial lesions (HSIL); LSIL, cannot exclude HSIL (LSIL-H); and atypical squamous cells, cannot exclude HSIL (ASC-H) during a 5-year period to evaluate the clinical significance of LSIL-H as a distinct cytological category.MethodsAll Pap tests with a diagnosis of LSIL-H, ASC-H, LSIL, and HSIL (January 1, 2004-July 20, 2009) were retrieved from our computer database. PPVs of cytological diagnostic categories for detecting CIN 2+ were compared.ResultsOf all Pap tests (n = 163,315), 1713 cases that had histological confirmation were included in the study. The LSIL-H diagnosis represented only 0.23% (n = 387) of all Pap tests and 9.3% of all cytological SILs (n = 4119). LSIL alone was associated with a significantly lower risk for CIN 2+ (PPV = 21%) as compared with LSIL-H (PPV = 40%). The results showed that the risk of CIN 2+ was intermediate for LSIL-H compared with unqualified LSIL (p < 0.005) and HSIL (p < 0.0001).ConclusionsThe current study is one of the largest LSIL-H series to date. Because of its intermediate status between LSIL and HSIL, LSIL-H should be considered a distinct diagnostic category, and specific cytomorphological criteria should be defined. The results suggest that an LSIL-H diagnostic category would aid in more rapid detection and treatment in some patients with CIN 2+.

Research Highlights► The risk of CIN 2+ was intermediate for LSIL-H compared with LSIL and HSIL. ► LSIL-H diagnosis would aid in more rapid detection in some patients with CIN 2+. ► LSIL-H should be considered a distinct category separate from LSIL and HSIL.