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. Cancer (Cancer Cytopathol) 2003;99:342–5. © 2003 American Cancer Society.

INK4a and conventionally counterstained with haematoxylin. The intensity of immunostaining in cases of squamous intraepithelial lesion (SIL) was assessed using a 0-3 scoring system. Interobserver agreement was calculated by k statistics. Results: Expression of p16INK4a was detected in 3 of 23 cases of WNL, 4 of 6 cases of LSIL, all cases of HSIL, 5 of 16 cases of ASC-US and 13 of 16 cases of ASC-H. Excluding two cases with no residual dysplastic cells in the immunocytochemistry, all cases of cervical intraepithelial neoplasia (CIN)2 or CIN3 at follow-up expressed p16INK4a and none of the p16 INK4a -negative cases showed a high-grade lesion at follow-up. No evident differences in pattern or intensity of p16INK4a expression were observed between the specimens of the study and control groups. Interobserver agreement was significantly better in the study group than in the group with conventional immunostaining (combined k 0.773 v 0.549; p,0.05), and still better, albeit statistically not significant, than with conventional immunostaining and cervical smear test together (combined k 0.773 v 0.642). Conclusion: Immunocytochemistry with p16INK4a and modified Papanicolaou counterstain may add to the cervicovaginal cytology the full potentiality of p16INK4a without the need of a further slide and the risk of loss of dysplastic cells, yet maintaining the typical morphological features of the smear test.