Objectives: The diagnosis of eosinophilic esophagitis (EoE) is based on histologic findings of eosinophilia in the esophageal squamous epithelium in patients presenting with esophageal symptoms. Variability in the degree of squamous epithelial eosinophil infiltration presents a challenge to diagnostic accuracy. We examined the histopathologic features in a well-defined cohort of children with EoE to derive an optimal number of biopsies needed for diagnosis.
Methods: A total of 30 patients diagnosed with EoE based on>15 eosinophils per high-power field (eos/HPF) were evaluated. The diagnosis of EoE was based on persistent esophageal eosinophilia following acid suppression therapy. All patients had mid and distal biopsy specimens that were analyzed along with 24-h pH probe studies.
Results: A total of 221 biopsy specimens were reviewed with a median of 7.8 (range, 5-8) specimens per patient. Eight patients demonstrated abnormal pH studies. The median eos/HPF was 41 (range, 0-288 eos/HPF). Using a criterion of>15 eos/HPF, the diagnostic sensitivity of a single biopsy was 73%, which increased to 84%, 97% and 100% for two, three and six biopsies, respectively. Five patients (17%) would not have met the criteria for diagnosis if biopsies were only taken from the mid esophagus whereas one patient (3%) would have been missed if only distal biopsies were analyzed.
Conclusions: Significant histologic variability exists among biopsy specimens from pediatric patients with EoE. Using the criterion of>15 eos/HPF, three biopsy specimens achieved a diagnosis of EoE in 97% of patients. Histopathologic changes consistent with EoE can persist following proton pump inhibitor therapy in patients with EoE and gastroesophageal reflux disease when the latter is defined by increased distal esophageal acid exposure.