Detection of Unsuspected Abnormalities by PAPNET-Assisted Review

Abstract

To determine the positive predictive value of abnormalities detected by PAPNET-assisted review of slides considered to show no abnormality on two manual screenings and to evaluate the repeatability of technical codes assigned by the PAPNET scanner. PAPNET-assisted review was performed on 19,805 slides that had been assessed as showing no abnormality on two occasions by manual screening plus 195 slides with abnormal cells seeded at random. Abnormalities detected by cytotechnologists were graded by cytopathologists and compared with the findings of later histology/cytology. On PAPNET-assisted review, the cytotechnologists identified 212 slides as containing unsuspected abnormalities; cytopathologists agreed with 76% (162/212) of these predictions. Later histology/cytology confirmed 54% (14/26) and 32% (33/102) of the predictions of high and low grade abnormality, respectively. The PAPNET scanner gave concordant technical codes for 94.8% of 2,690 slides that were submitted twice for scanning. Some additional abnormalities will be detected by a PAPNET-assisted review, even among slides considered negative on two manual screenings. However, many of these abnormalities will not be confirmed on later investigation and will thus appear to represent false positive cytology. The assigning of technical codes by the PAPNET machine is subject to a degree of variation on repeat evaluation of the same slides.