Diagnostic Disagreement among Pathologists Interpreting Breast Biopsies

Elmore et al in their article published in JAMA report their findings on diagnostic disagreement among 115 pathologists compared with a consensus panel.

The participating pathologists independently interpreted 240 cases, that included 23 cases of invasive breast cancer, 73 cases of ductal carcinoma in situ (DCIS), 72 cases with atypical hyperplasia (atypia), and 72 benign cases without atypia. Among the 3 consensus panel members, unanimous agreement of their independent diagnoses was 75%, and concordance with the consensus-derived reference diagnoses was 90.3%.

  

Compared with the consensus-derived reference diagnosis, the overall concordance rate of diagnostic interpretations of participating pathologists was 75.3%. Among invasive carcinoma cases 96% were concordant; among DCIS cases 84% were concordant, with 3% were over interpreted, and 13% were under interpreted; among atypia cases 48% were concordant, with 17% were over interpreted, and 35% were under interpreted; and among benign cases without atypia 87% were concordant. Disagreement with the reference diagnosis was statistically significantly higher among biopsies from women whose breasts were dense on prior mammograms.

In this study overall agreement between the individual pathologists’ interpretations and the expert consensus-derived reference diagnoses-was 75.3 percent, with the highest level of agreement 96 percent for invasive carcinoma and lower levels of agreement for DCIS 87 percent.  However, with atypical ductal hyperplasia the pathologists matched the experts only in 48 percent of the time.