Heterotopic Gastric Mucosa in Middle Esophagus Complicated with Esophageal Ulcers

Abstract

Heterotopic gastric mucosa (HGM) of esophagus, primarily occurring in cervical esophagus, is usually asymptomatic. A healthy woman (mid-40s) with postprandial heartburn was diagnosed with middle esophageal HGM and esophageal ulcers by esophagogastroduodenoscopy. Using 8-channel pH monitoring, a sensor near the HGM area detected postprandial acid phase (pH 3-4), while areas adjacent to the proximal and distal sensors were neutral, suggesting acid secretion from the HGM. A biopsy showed fundic gland tissue expressing H⁺/K⁺-ATPase and pepsinogen-I. Oral vonoprazan improved the clinical symptoms and endoscopic findings. This is the first report using 8-channel pH monitoring to diagnose extremely rare middle esophageal HGM.

Keywords: acid suppressive therapy; esophageal ulcer; heterotopic gastric mucosa; inlet patch; pH monitoring; potassium-competitive acid blocker.

Figure 1.

Upper endoscopy findings. (A) Heterotopic gastric mucosa was observed on the right wall of the middle thoracic esophagus along with shallow ulcers in the adjacent mucosa (indicated by colored arrows). (B) Narrow-band imaging with magnification endoscopy for the HGM revealed a brownish area clearly demarcated from the light-green squamous epithelium, and tubular microstructures were observed inside the lesion.

Figure 2.

Eight-channel pH sensor catheter developed in our department. (A) Four portable digital recorders are attached to the proximal end. (B) The flexible catheter measures 2.35 mm in diameter and is equipped with 8 pH electrodes along the distal end (red arrows) arranged at intervals of 1 cm on the vertical axis.

Figure 3.

(A) The pH monitoring catheter was inserted to position the heterotopic gastric mucosa between channels 5 and 6 with endoscopic observation, (B) which was also confirmed by fluoroscopy (white arrowhead indicates marker of heterotopic gastric mucosa). (C) Eight-channel pH monitoring revealed an acid phase of pH 3-4 appearing at channel 6 about 40 minutes after meals (red circles), while the adjacent proximal and distal channels exhibited a neutral level, suggesting acid secretion from the HGM area.

Figure 4.

Biopsy specimen. (A) The sampled tissue was satisfactorily smoothed, and a fine vertical section is shown. (B) Hematoxylin and Eosin staining demonstrated non-atrophic and little inflammatory fundic gland tissue. Immunohistochemical findings showed expression of (C) H⁺/K⁺-ATPase primarily in the upper layer and (D) pepsinogen-I in the lower layer, suggesting heterotopic gastric mucosa, fundic gland type.

Figure 5.

Endoscopic findings before and after acid suppressive therapy. (A) Shallow esophageal ulcers were noted adjacent to heterotopic gastric mucosa, and the surrounding mucosa was cloudy. (B) Following the administration of vonoprazan at 20 mg/day for 8 weeks, the ulcer was scarred, and vascular translucency improved. (C) The dosage was decreased to 10 mg, and the mucosal status was found to be well maintained 16 weeks later. (D) Narrow-band imaging with magnification endoscopy of the adjacent ulcer scar (blue arrow) showed regularly arranged, dilated intrapapillary capillary loops.