Clinical significance of the diagnosis of low-grade squamous intraepithelial lesion, cannot exclude high-grade squamous intraepithelial lesion.

Background: The diagnosis of low-grade squamous intraepithelial lesion (LSIL), cannot exclude high-grade squamous intraepithelial lesion (LSIL-H) was not included in the 2001 Bethesda System. It is used in some institutions to diagnose cases that fulfill criteria for both the diagnosis of LSIL and atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H). In this study, the authors reviewed their experience with cases reported as LSIL-H during a 4-year interval.
Methods: Clinical information and histologic follow-up data were retrieved for Papanicolaou (Pap) tests (PTs) that were diagnosed as LSIL-H, LSIL, ASC-H and high-grade squamous intraepithelial lesion (HSIL) from January 1, 2004 to December 31, 2007.
Results: Of 235,645 PTs (97% SurePath) that were processed during the study period, the laboratory diagnosed 0.52% as ASC-H, 2% as LSIL, 0.30% as LSIL-H, and 0.39% as HSIL. Biopsy follow-up was available for 47%, 49%, 56.7% and 74% of these cases, respectively. Cervical intraepithelial neoplasia 2 (CIN-2) and CIN-3 or more severe lesions (CIN-3+) were identified on follow-up cervical biopsy more often in women who had diagnoses of LSIL-H and ASC-H (33.14% and 26.33%, respectively) than in women who had a diagnosis of LSIL (16.11%).
Conclusions: The similarity of histologic follow-up results between LSIL-H and ASC-H suggested that the management of women who have a diagnosis of LSIL-H should be similar to the management of women who have a diagnosis of ASC-H.
((c) 2009 American Cancer Society.)