Comparison of the clinical significance of the Papanicolaou test interpretations LSIL cannot rule out HSIL and ASC‐H

Despite the two‐tiered classification of dysplasia in The Bethesda System (TBS), rare cases fall into the category squamous intraepithelial lesion (SIL) of indeterminate grade. These Pap tests are often interpreted as “LSIL/ASC‐H” or “LSIL” with a comment indicating the presence of cells with features approaching HSIL. Patients with LSIL/ASC‐H have a significant risk of CIN 2 or worse (29–61.5%) on follow‐up cervical biopsies, similar to the risk of CIN 2 or worse in patients with ASC‐H Pap tests (24–68%). The purpose of this study was to compare patients with ASC‐H and LSIL/ASC‐H Pap tests. Women with LSIL/ASC‐H had a slightly lower incidence of CIN 2 or worse (PPV = 35.6%, 95% CI: 29.8–41.4%) on follow‐up cervical biopsy than the control ASC‐H group (PPV = 40.2%, 95% CI: 31.9–56.3%); this difference was not statistically significant. The difference in the distribution of the biopsy results between the two groups was statistically significant (P < 0.001). The current guidelines for the management of cervical cytologic abnormalities from the American Society for Colposcopy and Cervical Pathology (ASCCP) advocate similar treatment algorithms for both LSIL and ASC‐H. The main difference is the option of cytologic follow‐up or HPV testing for certain “special populations,” as an alternative to colposcopy, for LSIL Pap test results. Based on our results, we recommend (1)LSIL/ASC‐H to be added to TBS classification and (2) Pap test cases of LSIL/ASC‐H may need to be clinically followed in a manner similar to ASC‐H, i.e., colposcopy for all patients. Diagn. Cytopathol. 2010. © 2009 Wiley‐Liss, Inc.