Objective: The aim of this study involving general pathologists was to assess interobserver reproducibility in the pathologic diagnosis of borderline ductal proliferative breast diseases.
Methods: Ten general pathologists independently reviewed 43 specimens chosen to represent the spectrum of borderline ductal proliferative breast lesions. All slides were blindly reviewed without given standardized criteria, and were classified as either mild usual hyperplasia, moderate-severe usual hyperplasia, mild atypical hyperplasia, moderate-severe atypical hyperplasia, ductal carcinoma in situ, or ductal carcinoma in situ with invasion. According to the years of training, these 10 general pathologists were divided into the experienced group and the less trained group. Interobserver agreement was statistically analyzed using Kappa statistic. Then, by comparing all the diagnoses of individual pathologist with the consensus opinion confirmed by two breast pathologists in terms of Page standard, we acquired the diagnostic accuracy and ascertained the undue diagnosis.
Results: The ten general pathologists' interobserver reproducibility in the diagnosis of borderline ductal proliferative breast diseases was rather low, especially that in their diagnosis of atypical hyperplasia. The reproducibility and accuracy were slightly higher in the experienced pathologists than in the less trained pathologists. Some pathologists made over-diagnosis or under-diagnosis of the lesions to different degrees. However, when the categories of diagnostic terms were simplified, the interobserver reproducibility increased.
Conclusion: The use of standardized criteria is an important approach to increasing the diagnostic reproducibility and accuracy.