Are pathologists accurately diagnosing eosinophilic esophagitis in children? A 9-year single academic institutional...

Our aims were to evaluate (a) whether the incidence of eosinophilic esophagitis (EE) in children has increased, (b) whether the histologic diagnosis of EE has been accurate, and (c) potential interobserver variability in the counting of intraepithelial eosinophils in esophageal biopsies. A total of 1215 pediatric endoscopic esophageal biopsies were performed. In total, 289 biopsies were reviewed by one pathologist based on one of the following original histologic diagnoses: EE, reflux esophagitis (RE), or acute/chronic inflammation. EE was diagnosed when at least one high-power field (HPF) contained > or = 20 intraepithelial eosinophils. According to the first pathologist, 104 biopsies had a histologic diagnosis of EE; the prevalence remained relatively stable, ranging from 5.5 to 11 per 100 biopsies annually. In 36 cases, the reporting pathologist correctly diagnosed EE, and in another 34, EE was included in the differential diagnosis. From January 1997 to December 1998, the pathologist either correctly diagnosed EE or included it in the differential diagnosis in 6/13 cases. In contrast, from January 2004 to December 2005, 32/37 cases were included. In 34/104 cases, EE was misdiagnosed as RE. No case of RE was misdiagnosed as EE.A total of 58 cases had pathology reports that quantified the densest number of eosinophils per HPF. The agreement rate was 94.8%, with a kappa value of 0.888. The incidence of EE in children has been stable from January 1997 to December 2005. Overall, pathologists recognized EE in two thirds of cases. The increased diagnostic accuracy over time suggests pathologists are more aware of EE.