The conventional cytology was interpreted independently by two cytopathologists, both of whom are blinded to the DIA results. The conventional cytologic diagnosis were classified as no abnormal cells, atypical cells, suspicious malignant cells and malignant cells. The specimens were examined by two experienced cytopathologists. Any disagreement on specimens would refer to a third cytopathologist to provide a final consensus. The former two diagnosis were determined to be positive, and the latter two to be negative.