There is suboptimal inter-observer agreement, even among expert gastrointestinal pathologists, in the diagnosis of low-grade dysplasia in patients with Barrett’s esophagus.
Dr Prateek Sharma and colleagues from Missouri, USA analyzed histopathologic criteria required for a diagnosis of low-grade dysplasia using the new subcategories of low-grade dysplasia with inflammatory and dysplastic features.
The research team categorized each diagnosis based on the level of confidence, and assessed inter-observer agreement among gastrointestinal pathologists from 5 tertiary centers in the United States and Europe.
In the first phase of the study, 3 pathologists held a consensus conference at which they discussed the diagnostic criteria for low-grade dysplasia.
|That overall κ value for diagnosis was 0.43|
In the second phase, 79 slides from patients with Barrett’s esophagus were identified, randomly assigned to 7 pathologists, and interpreted in a blinded fashion.
κ Values were calculated for inter-observer agreement.
The researchers found that overall κ value for diagnosis was 0.43.
When categorized based on degree of dysplasia, the κ value was 0.22 for non-dysplastic Barrett’s esophagus, 0.11 for low-grade dysplasia, and 0.43 for high-grade dysplasia.
The team noted that when all pathologists made a diagnosis with high confidence, the inter-observer agreement was substantial among the US pathologists, and European pathologists.
The researchers determined that κ values for all diagnoses made by European pathologists were higher than those made by US pathologists.
Dr Sharma's team concludes, "In an analysis of criteria used in histopathologic diagnosis of low-grade dysplasia, we did not observe improvement in level of agreement among experienced pathologists, even after accounting for inflammation."
"The level of inter-observer agreement increased with level of pathologist confidence."
"There was also a difference in reading of histopathology samples of Barrett’s esophagus tissues between US and European pathologists."