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, LSIL, and HSIL in the detection of high-grade cervical lesions with a review of the literature.

OBJECTIVE: We 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.

METHODS: All 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.

RESULTS: Of 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).

CONCLUSIONS: The 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+.