Heterotopic Gastric Mucosa in the Distal Part of Esophagus in a Teenager

Abstract

Heterotopic gastric mucosa (HGM) of the esophagus is a congenital anomaly consisting of ectopic gastric mucosa. It may be connected with disorders of the upper gastrointestinal tract, exacerbated by Helicobacter pylori. The diagnosis of HGM is confirmed via endoscopy with biopsy. Histopathology provides the definitive diagnosis by demonstrating gastric mucosa adjacent to normal esophageal mucosa. HGM located in the distal esophagus needs differentiation from Barrett's esophagus. Barrett's esophagus is a well-known premalignant injury for adenocarcinoma of the esophagus. Malignant progression of HGM occurs in a stepwise pattern, following the metaplasia–dysplasia–adenocarcinoma sequence.

We present a rare case of a teenage girl with HGM located in the distal esophagus, associated with chronic gastritis and biliary duodenogastric reflux. Endoscopy combined with biopsies is a mandatory method in clinical evaluation of metaplastic and nonmetaplastic changes within HGM of the esophagus.

INTRODUCTION

Heterotopic gastric mucosa (HGM) of the esophagus was first defined in 1805 by Schmit during a postmortem examination.¹ HGM of the esophagus is mostly localized in the upper esophagus and termed inlet patch.² An inlet patch is a congenital anomaly and most of these are largely asymptomatic. It usually cannot be diagnosed easily. Rarely, it can also be found in other parts of the esophagus.^3,4 HGM is reported in up to 10% of the general population among numerous reports and epidemiologic studies which have been essentially performed in adult population.⁵ Pediatric data are still limited. There are case reports showing that this injury may play a role in the development of stenosis, ulcer, perforation, or esophagotracheal fistula related to its capability of hydrochloric acid secretion.^6,7 Malignant progression of HGM occurs in a stepwise pattern, following the metaplasia–dysplasia–adenocarcinoma sequence.^8,9 These complications may be exacerbated by Helicobacter pylori.¹⁰

We present a case of esophageal gastric heterotopia that was located in the distal esophagus and needed differentiation from Barrett's esophagus.

CASE REPORT

A Caucasian teenage girl, 16 years old, followed up for the last 3 years, was initially admitted in the V-th Pediatric Gastroenterology Clinic of “St Mary” Children's Emergency Hospital, Iasi, Romania, for postprandial epigastric pain.

Over the 3 years, her physical examination revealed good generally status, abdominal pain localized in the left hypochondrium and/or in epigastrium, without any other pathological elements at examination. The informed consent was obtained each time the patient was hospitalized.

Laboratory tests: complete blood count showed normal results.

The upper gastrointestinal endoscopy revealed the presence of multiple pseudo-polypoid formations with slightly eroded tip, measuring approximately 0.5 cm, in the lower 1/3 of esophagus (Fig. 1A, B); stomach with hypertrophic folds, with nodular purpuric congestion and erosions covered with hematic deposit in the antral region, sero-mucous fluid stasis of bile (Fig. 2), duodenum with diffuse congestion without ulceration, friable mucosa.

FIGURE 1.

(A) Gastric heterotopia in the distal part of esophagus; (B) gastric heterotopia in the distal part of esophagus.

FIGURE 2.

Nodular purpuric gastritis with hypertrophic folds; biliary reflux.

Histopathologic examination of the biopsy samples taken from the pseudo-polypoid formations showed acid-secreting, oxyntic-type, glandular, gastric epithelium, attached to the esophageal epithelium, without intestinal metaplasia or dysplasia. There were a few microhemorrhagic outbreaks and a discrete inflammatory infiltrate (Fig. 3A, B, C). Our histopathologic examination did not show intestinal metaplasia or Goblet cells (Alcian blue stain), which are important for the diagnosis of Barrett's esophagus. Five biopsy samples were taken, 3 from inlet patches which revealed gastric epithelium and 2 down (distal) from these injuries where squamous epithelium was found. These inlet patches were clearly separated from the stomach by squamous epithelium. The test was negative for H. pylori.

FIGURE 3.

Histopathologic examination (histopathologic examination [HE] × 100): A—gastric epithelium attached to the esophageal epithelium. B—inflammation and microhemorrhages in the esophageal epithelium. C—inflammation and microhemorrhages in the gastric epithelium.

At colonoscopy, the mucosa of rectum, sigmoid and descending colon appeared normal, without evidence of diverticulosis or polyps.

DISCUSSIONS

HGM is a congenital defect that is usually no >1 cm. HGM can be <1 cm or >5 cm.¹¹ The inlet patch is considered an inherited anomaly. Inlet patches represent the incomplete transformation from columnar to squamous epithelium during embryonic development.¹² The process is starting from the middle third of the esophagus and extending proximally and distally. The last esophageal segment reepithelialized is the most proximal. HGM develops on incomplete reepithelialization. The persisting columnar cells at birth are usually proximally over the upper third of the esophagus or, much less frequently, distally over the esophagogastric junction. The preferential localization of HGM in the cervical esophagus is explained by the temporal difference in the stratified reepithelialization of both ends of the esophagus.¹³

It is generally accepted that Barrett's esophagus is an acquired metaplastic change because of chronic gastroesophageal reflux. Another proposed theory on the development of HGM involves metaplastic transformation of the squamous lining to columnar from chronic acid injury as seen in Barrett's esophagus.¹⁴ These are based on similarities in the mucin and staining characteristics with CK7 and CK20 between Barrett's esophagus and HGM.¹⁵ It is postulated that chronic acid exposure results in inflammation that leads to reactivation or proliferation of remnant columnar mucosa. These remnants of columnar mucosa are present as microscopic foci in the esophageal lining or are covered by squamous mucosa. With chronic irritations, these foci develop into larger patch resulting in the formation of island of columnar mucosa, HGM.¹⁶

It was also proposed that the origins of HGM may be different, congenital in children and acquired in adult.¹⁵

There are several factors that favor the congenital origin hypothesis. The embryogenesis of esophagus can explain the profiles of HGM, proximal location or the distal part of the esophagus. The children do not have sufficient duration of acid exposure to induce changes suggested by the acquired theory.

The origin of esophageal HGM has not been finally determined as yet, and further investigations are needed to resolve these questions.³ But from current available evidence, it seems more likely that HGM is congenital in origin.

Most inlet patches are solitary and extend longitudinally. In the patients with multiple patches, they tend to be small.¹⁷ In our case, we have described them as multiple pseudo-polypoid formations with slightly eroded tip.

Most inlet patches are clinically asymptomatic.¹⁸ The underlying factor of the symptoms, clinical findings, and complications is the secretion of acid. Only in 10% of cases they do produce clinical symptoms, such as chest and throat pain, dysphagia, globus sensation, shortness of breath, chronic cough and hoarseness.¹⁹ In our case, the patient presented with postprandial epigastric pain only. In our patient, HGM was associated with discrete inflammation, chronic gastritis, and biliary duodenogastric reflux. The HGM was grade I according to the proposed clinicopathologic classification (Table 1).³

TABLE 1.

Clinicopathologic Classification of Esophageal HGM

Ectopic gastric mucosa can occur anywhere along the gastrointestinal tract. For this reason, we performed the colonoscopy which was normal.

Barrett's esophagus is characterized histologically by an admixture of 3 columnar epithelia: cardiac, oxyntocardiac, and intestinal metaplasia. Histologically, HGM consists of oxyntic mucosa with mucus-secreting columnar cells, chief cells, and parietal cells.³

Barrett's esophagus is widely considered to be a consequence of longstanding acid induced injury commencing as an erosive esophagitis and progressing over years to columnar and intestinal metaplasia of the squamous epithelium. In our case, the patient had biliary duodenogastric reflux, without esophagitis. It needed a histopathologic confirmation, that is the presence of intestinal metaplasia.²⁰ Our histopathologic examination revealed just a discrete inflammatory infiltrate, without intestinal metaplasia or dysplasia. In Barrett's esophagus, columnar epithelium extends from the stomach up to the gastroesophageal junction into the esophagus.²⁰ It looks like a continuation of gastric mucosa. In our case, columnar epithelium was not the continuation of gastric mucosa; it was clearly separated from the stomach by squamous epithelium. There were multiple pseudo-polypoid formations, which can indicate that all lesions are congenital and not reflux related as in Barrett's esophagus. Furthermore, over the last 3 years as we have followed up the patient, the injuries have remained the same in number and pathology. Based on studies from the literature, we reevaluated the findings in our patient as gastric heterotopia and not Barrett's esophagus.

A strong affinity of H. pylori to colonize gastric type mucosa has been demonstrated.²¹ In our case, colonization of HGM and of stomach with H. pylori was not observed.

This type of gastric heterotopia can cause reflux-like symptoms, which resolved very well with proton pump inhibitor treatment.²² No treatment is required for asymptomatic HGM.

Strictures are treated with serial dilatation and should be biopsied to rule out malignancy.

It can be discussed about an ablation of the gastric heterotopia's area. We did not try it because of the lack of support in the literature.

The cyclooxygenase (COX) enzyme catalyzes the conversion of arachidonic acid to prostaglandins.²³ There are 2 COX isoforms in humans: COX-1 and COX-2. Overexpression of COX-2 has numerous effects on cells: increased cell proliferation, decreased apoptosis rate, stimulation of angiogenesis, and increased invasive and metastatic potential.^24,25 Neoplastic transformation in gastric heterotopia is rare. In contrast to Barrett's esophagus, gastric heterotopia has not been accepted as a premalignant lesion.³ COX-2 is overexpressed in Barrett's esophagus and is involved in the sequence of events that lead to malignant transformation.²⁶

We are following the evolution by endoscopy every 6 months and multiple esophageal biopsies once a year in order to monitor any change in HGMs.

CONCLUSIONS

We are presenting a case with multiple pseudo-polypoid formations of gastric heterotopia that are located in the distal part of the esophagus. HGM should not be overlooked in the diagnostics. Endoscopy combined with histopathologic and microbiological analysis of biopsies is definitely a mandatory method in clinical evaluation of metaplastic and nonmetaplastic changes within HGM of the esophagus.

When, during superior digestive endoscopy, columnar-lined esophagus is observed in the distal esophagus, not being in continuity with gastric mucosa, the diagnosis of HGM must be thought and confirmed histologically by the presence of pure oxyntic mucosa.