Should esophageal biopsies be taken during endoscopy to rule out Eosinophilic Esophagitis (EOE)?

Esophageal Biopsies Should Be Taken During Endoscopy to Rule Out Eosinophilic Esophagitis

Esophageal biopsies should always be obtained during endoscopy in patients with suspected EoE, even when the esophagus appears normal endoscopically, as this is the only reliable diagnostic test for this condition. 1

Indications for Esophageal Biopsies

Adults

• Biopsies should be taken in all adults with:
  • Dysphagia or food bolus obstruction (regardless of endoscopic appearance) 1
  • Endoscopic signs associated with EoE (rings, furrows, white plaques, mucosal edema, fragile mucosa, narrow caliber esophagus, strictures) 1
  • Normal-appearing esophagus but symptoms suspicious for EoE 2

Children

• Biopsies should be taken in all children with:
  • Any upper gastrointestinal symptoms warranting endoscopy 1
  • GERD symptoms refractory to PPI therapy 1
  • Failure to thrive, vomiting, abdominal pain, dysphagia, or food impaction 1

Biopsy Protocol

• Multiple biopsies from at least two esophageal levels (proximal and distal) 1
• Target areas of apparent inflammation when present 1
• 2-4 biopsies from each level is recommended 1
• Consider gastric and duodenal biopsies in children to exclude other causes of esophageal eosinophilia 1

Diagnostic Yield and Rationale

• 7-17% of patients with biopsy-proven EoE have a normal-appearing esophagus on endoscopy 1
• In patients with dysphagia and normal endoscopic appearance, approximately 10% will have EoE on biopsy 2
• Endoscopic features of EoE have limited sensitivity (15-46%) but high specificity (90-95%) 1
• The diagnostic threshold for EoE is ≥15 eosinophils per high-power field in at least one biopsy specimen 1, 3

Special Considerations

• PPI therapy should be withdrawn for at least 3 weeks prior to diagnostic endoscopy and biopsy to avoid masking EoE 4
• PPIs can suppress esophageal eosinophilia below the diagnostic threshold in approximately 51% of patients 4
• Document PPI discontinuation status on endoscopy reports and histology request forms 4
• Early diagnosis is crucial as delayed diagnosis increases risk of esophageal fibrosis and stricture formation 4

Pitfalls to Avoid

• Relying solely on endoscopic appearance for diagnosis (insufficient sensitivity)
• Obtaining too few biopsies (decreases diagnostic yield)
• Performing biopsies while patient is on PPI therapy (may mask diagnosis)
• Failing to biopsy normal-appearing esophagus in patients with dysphagia
• Neglecting to document medication status when interpreting biopsy results

Endoscopy with multiple esophageal biopsies remains the gold standard for diagnosing EoE. Given the significant impact of untreated EoE on morbidity and quality of life through progressive fibrosis, stricture formation, and recurrent food impactions, obtaining esophageal biopsies during endoscopy is essential for proper diagnosis and management of this increasingly recognized condition.