Endoscopic Diagnosis of Eosinophilic Esophagitis: Basics and Recent Advances

Abstract

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated inflammatory disease, characterized by esophageal dysfunction and intense eosinophil infiltration localized in the esophagus. In recent decades, EoE has become a growing concern as a major cause of dysphagia and food impaction in adolescents and adults. EoE is a clinicopathological disease for which the histological demonstration of esophageal eosinophilia is essential for diagnosis. Therefore, the recognition of the characteristic endoscopic features with subsequent biopsy are critical for early definitive diagnosis and treatment, in order to prevent complications. Accumulating reports have revealed that EoE has several non-specific characteristic endoscopic findings, such as rings, furrows, white exudates, stricture/narrowing, edema, and crepe-paper esophagus. These findings were recently unified under the EoE endoscopic reference score (EREFS), which has been widely used as an objective, standard measurement for endoscopic EoE assessment. However, the diagnostic consistency of those findings among endoscopists is still inadequate, leading to underdiagnosis or misdiagnosis. Some endoscopic findings suggestive of EoE, such as multiple polypoid lesions, caterpillar sign, ankylosaurus back sign, and tug sign/pull sign, will aid the diagnosis. In addition, image-enhanced endoscopy represented by narrow band imaging, endocytoscopy, and artificial intelligence are expected to render endoscopic diagnosis more efficient and less invasive. This review focuses on suggestions for endoscopic assessment and biopsy, including recent advances in optical technology which may improve the diagnosis of EoE.

Keywords: EREFS scoring; diagnostic accuracy; endoscopic diagnosis; eosinophilic esophagitis; image enhanced endoscopy.

Figure 1

A typical patient with EoE complicated by food impaction (33 years old, male). (a). Chest CT. Esophageal lumen is dilated and filled with structures that appear to be impacted food. (b,c). Urgent endoscopy. Food bolus (piece of meat) is present in the middle esophagus. Impacted food is removed by letting it drop into the stomach, pushing with an endoscope equipped with a clear distal attachment hood. (d). Subtle rings and furrows are visible by narrow band imaging, suspicious of EoE. (e). Rings and furrows are more distinctly observed in the re-endoscopy after one week without PPI. (f). Esophageal biopsies show a peak of 52 eosinophils/hpf. EoE, eosinophilic esophagitis; PPI, proton pump inhibitor.

Figure 2

Characteristic endoscopic findings of EoE. (a). Edema. Decreased vascularity or loss of it is evident. (b). Rings. Multiple concentric rings are almost constitutively present (esophageal trachealization). (c). White exudates. White plaques, difficult to distinguish from Candida, are present. (d). Furrows. Multiple crack-like lines running longitudinally are presented. (e). Stricture. Web-like appearance with proximal esophageal dilatation is displayed. (f). Narrow caliber esophagus. Esophageal narrowing with tubular-appearing lumen is demonstrated. EoE, eosinophilic esophagitis.

Figure 3

Esophageal erosion, furrows and rings in GERD and EoE, and feline esophagus in normal esophagus. (a,b). Coexistence of furrows in EoE (arrowhead) and longitudinal erosion in GERD (black arrow). Biopsy should be obtained just above on furrows (asterisk). (c). The visibility of furrows is enhanced after esophageal biopsies with blood pouring on the furrows. (a–c, same patient; a, WLI; b, NBI). (d). Mild rings observed in erosive esophagitis. (e,f). Feline esophagus. Transient and subtle concentric rings are observed in the normal esophagus (e,f, same patient). EoE, eosinophilic esophagitis; GERD, gastroesophageal reflux disease; WLI, white light imaging; NBI, narrow band imaging.

Figure 4

Narrow caliber esophagus and crepe-paper esophagus. Esophagogram shows narrow caliber esophagus from the upper to mid esophagus, with a diameter of 8.3–14.4 mm. (a). Mucosal tear developed at upper (b), mid (c), and lower end (d) of the esophagus after regular passage of peroral endoscope.

Figure 5

Endoscopic findings by IEE in EoE. (a). Beige color mucosa (BLI) (b). Magnified image of the area indicated by the white frame in Figure (a). Dot-like intrapapillary capillary loops are seen. Cyan submucosal vessels are invisible (BLI). (c). Yellowish mucosa (LCI, proximal esophagus). (d). Yellowish mucosa (LCI, middle esophagus). IEE, image enhanced endoscopy; EoE, eosinophilic esophagitis; BLI, blue laser imaging; LCI, linked color imaging.

Figure 6

Endoscopic image sets consisting of WLI, BLI and LCI in EoE. (a) WLI; (b) BLI; (c) LCI (a–c, same patient). Rings and edema in the lower esophagus are more clearly visible in LCI compared to WLI and BLI. EoE, eosinophilic esophagitis; WLI, white light imaging; NBI, narrow band imaging; BLI, blue laser image; LCI, linked color imaging.

Figure 7

Other endoscopic findings related to EoE. (a). Multiple polypoid lesions (b). Ankylosaurus back sign (c). Tug sign/pull sign: with pulling by the biopsy forceps, a large amount of esophageal mucosa is lifted as a tent and caught in the forceps opening. (d). Caterpillar sign. EoE, eosinophilic esophagitis.

Figure 8

Localized EoE in the lower end of the esophagus. Endoscopic abnormalities are localized at a small area of 1–2 cm in the lower end of the esophagus. (a,b). Furrows and edema are present in the lower end of the esophagus (same patient, a, WLI; b, NBI). (c,d). Furrows, rings and edema in the lower end of the esophagus (same patient, c, WLI; d, NBI). (e). No abnormal findings appear to be found under full expansion of the esophageal lumen (WLI). (f–h). Reducing the esophageal wall tension increases the visibility of furrows (arrow) and edema. Dynamic observation controlling the extensibility of the esophageal wall increases the visibility of furrows and edema (same patient, f, WLI; g, BLI; h, LCI). EoE, eosinophilic esophagitis; WLI, white light imaging; NBI, narrow band imaging; BLI, blue laser imaging; LCI, linked color imaging.