Accuracy of diagnosis of atypical glandular cells - Conventional and ThinPrep

The incidence of glandular cervical malignancy is steadily increasing. Glandular abnormalities are more frequently diagnosed on cervical smears. In this study, we attempt to evaluate our experience with glandular cytology and to assess the sensitivity and specificity of the ThinPrep (TP) over conventional Papanicolaou (Pap) smears. Glandular abnormalities during a 3-yr period from October 2000 to October 2003 were retrieved from our cytology database. The study group comprised smears from 369 patients, 272 conventional Pap smears (CPSs) and 97 TP from a total of 400,184 smears. The types of glandular abnormalities were tabulated following a modified Bethesda classification. Correlation with histology and follow-up cytology was achieved in all but six patients. Significant lesions were identified in 116/272 (PPV 42.6%) of CPSs and 58/97 (PPV 58.9%) TPs. Pure glandular abnormalities numbered 125 conventional and 51 TP; significant lesions identified in this group were 36/125 (PPV 28.8%) CPS and 26/51 (PPV 50.9%) TP. Statistical analysis showed significant differences for positive predictive values of TP and CPS and a suggestion of increased sensitivity. The main limiting factor was small numbers of glandular abnormalities and a desirable longer study time.