Intercenter Study of Interobserver Variability With Optical and Digital Imaging in Cervicovaginal Cytology. Simulation of a Quality Control Program.

INTRODUCTION

Participation in diagnostic intercomparison programs is a mandatory requirement for accreditation of cytology laboratories. Results described by these programs in cervico vaginal cytology (CVC) show a significant number of discrepancies. We hypothesised whether the use of IA systems, such as the ThinPrep Genius system, would improve diagnostic concordance.

METHODS

We simulated an intercomparison program between two centres in which four observers used the same 30 cases of CVC with negative diagnoses, ASCUS, LSIL and HSIL and observed them with light optic microscopy (OM) and two Genius (G1 and G2) systems, one from each centre.

RESULTS

The diagnostic agreement between OM and the two Genius was similar, with overall agreement values of 82% for G1 and 78% for G2 and OM, and similar kappa values for the three techniques. However, both Genius diagnosed glandular lesions that were not included in the selected cases and were not diagnosed with OM.

CONCLUSION

The concordance obtained in both OM and Genius is acceptable and falls within the range of that obtained in what is described in intercomparison programs. We must consider the greater affinity for diagnosing glandular lesions with Genius and the fact that there may be discrete differences between two different devices, probably due to calibration.