ThinPrep versus conventional Papanicolaou smear in the cytologic follow-up of women with equivocal cervical smears

BACKGROUND: The purpose of the current study was to compare the efficacy of liquid-based cytology and conventional smears in the cytologic follow-up of cases with "atypical squamous cells, cannot exclude a high-grade lesion" (ASC-H) or "atypical glandular cells" (AGC). METHODS: Cytologic follow-up was performed on 214 cases with ASC-H/AGC diagnosis an conventional smears using either ThinPrep (n = 100) or conventional Papanicoloau (Pap) tests (n = 114). Results were then compared with further histologic and/or cytologic follow-up. RESULTS: Repetition on conventional smears enabled a definite diagnosis (within normal limits WNL], squamous intraepithelial lesion SIL] or carcinoma) in 58 cases (50.9%). ASC/AGC was confirmed in 50 cases (43.9%), and 6 of the smears (5.3%) were inadequate. WNL, SIL, or carcinoma was diagnosed in 82 (82.0%) cases by following the patients with ThinPrep cytology, whereas ASC or AGC was confirmed in 18 cases (18.0%). No inadequate specimens were found. A diagnosis of SIL or greater (SIL +) was confirmed histologically in 11 of 11 (100.0%) conventional smears and in 31 of 34 (91.2%) ThinPrep specimens. Of the 87 WNL specimens, 9 (8 conventional smears and 1 ThinPrep specimen) developed a histologically confirmed SIL during further follow-up. Specimen adequacy was significantly better in the ThinPrep specimens compared with conventional smears. CONCLUSIONS: Because of better specimen adequacy, ThinPrep cervical cytology appears to significantly reduce the occurrence of ASC/AGC compared with conventional Pap smears.