Interobserver reproducibility in the diagnosis of flat epithelial atypia of the breast

Frances P. O'Malley, Syed K. Mohsin, Sunil Badve, Shikha Bose, Laura C. Collins, Marguerite Ennis, Celina G. Kleer, Sarah E. Pinder, Stuart J. Schnitt

Research output: Contribution to journalArticle

71 Scopus citations


Columnar cell lesions (CCLs) of the breast with low-grade/monomorphic-type cytologic atypia are being identified increasingly in biopsies performed owing to mammographic microcalcifications. The WHO Working Group on the Pathology and Genetics of Tumours of the Breast recently introduced the term 'flat epithelial atypia' (FEA) for these lesions. However, the ability of pathologists to reproducibly diagnose FEA and to distinguish it from CCLs without atypia has not been previously evaluated. Eight pathologists with an interest in breast pathology participated in a study to address this issue. The study reference pathologist provided the other seven study pathologists with a Powerpoint tutorial that included written criteria for, and representative images of, FEA and CCLs without atypia (ie, columnar cell change and columnar cell hyperplasia). Following review of the tutorial, the study pathologists examined images in Powerpoint format from 30 CCLs and were instructed to categorize each as either 'FEA' or 'not atypical'. Overall agreement among the eight pathologists was 91.8% (95% CI, 84.0-96.9%), and the multi-rater kappa value was 0.83 (95% CI, 0.67-0.94), which is within the 'excellent agreement' range. Agreement was slightly better for determining absence of FEA (92.8%: 95% CI, 84.1-97.4%), than for determining its presence (90.4%: 95% CI, 79.9-96.7%). We conclude that the diagnosis of FEA and its distinction from CCLs without atypia is highly reproducible with the use of available diagnostic criteria.

Original languageEnglish (US)
Pages (from-to)172-179
Number of pages8
JournalModern Pathology
Issue number2
StatePublished - Feb 1 2006


  • Breast
  • Columnar cell hyperplasia
  • Flat epithelial atypia
  • Interobserver reproducibility

ASJC Scopus subject areas

  • Pathology and Forensic Medicine

Fingerprint Dive into the research topics of 'Interobserver reproducibility in the diagnosis of flat epithelial atypia of the breast'. Together they form a unique fingerprint.

  • Cite this

    O'Malley, F. P., Mohsin, S. K., Badve, S., Bose, S., Collins, L. C., Ennis, M., Kleer, C. G., Pinder, S. E., & Schnitt, S. J. (2006). Interobserver reproducibility in the diagnosis of flat epithelial atypia of the breast. Modern Pathology, 19(2), 172-179.