Small intestine & ampulla
Congenital anomalies
Heterotopic gastric mucosa
Authors: Aastha Chauhan, M.D., Khalid Amin, M.D.
Editorial Board Member: Aaron R. Huber, D.O.
Deputy Editor-in-Chief: Catherine E. Hagen, M.D.
Last author update: 7 June 2021
Last staff update: 7 June 2021
Copyright: 2003-2024, PathologyOutlines.com, Inc.
PubMed Search: Heterotopic gastric mucosa[TI] small intestine
Table of Contents
Definition / general | Essential features | Terminology | ICD coding | Epidemiology | Sites | Pathophysiology | Etiology | Clinical features | Diagnosis | Radiology description | Radiology images | Prognostic factors | Case reports | Treatment | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Molecular / cytogenetics description | Sample pathology report | Differential diagnosis | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Chauhan A, Amin K. Heterotopic gastric mucosa. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/smallbowelheterotopicgastric.html. Accessed May 12th, 2024.
Definition / general
- Mature gastric tissue found outside the stomach
- Gastric fundic heterotopia represents a developmental anomaly and is frequently associated with Meckel diverticulum
Essential features
- Developmental anomaly characterized by ectopic gastric mucosa outside the stomach
- Histologically composed of foveolar epithelium with specialized antral glands with or without oxyntic mucosa
- Clinical features can vary from asymptomatic to abdominal pain, obstruction, intussusception, perforation, palpable mass, ulceration, stricture, etc., depending on the site
- Treatment is surgical removal of ectopic mucosa for symptomatic lesions
Terminology
- Heterotopic gastric mucosa (HGM) or ectopic gastric mucosa
ICD coding
Epidemiology
- Incidence in the duodenum varies from 0.5 to 14.3% (Pathol Res Pract 2011;207:148)
Sites
- Can be found in oral cavity, esophagus, duodenum, jejunum, ileum, rectum, anal canal, gallbladder and bile duct
- Occurrence in the small intestine is rare unless associated with remnants of Meckel diverticulum (Case Rep Gastroenterol 2020;14:609)
- Commonly occurs in the first and second portion of the duodenum (Int J Clin Exp Pathol 2012;5:46)
Pathophysiology
- Error in the differentiation of pluripotent primitive endoderm stem cells could lead to the gastric mucosa being present anywhere throughout the gastrointestinal tract
- CDX2 stimulates markers of enterocyte differentiation; null mutation of CDX2 can lead to the development of ectopic lesions with a gastric phenotype in the midgut endoderm (J Cell Biol 1997;139:1553)
Etiology
- Mainly a congenital malformation
Clinical features
- Symptoms caused by gastric heterotopia depend on location, as well as size of the heterotopic tissue
- In the majority of cases, patients are asymptomatic due to the small size of the lesion and diagnosis is made incidentally on endoscopy performed for other indications
- In both small and large intestines, it can give rise to abdominal pain, obstruction, intussusception, perforation, palpable mass, ulceration, stricture, bleeding per rectum and anemia (J Pediatr Surg 2008;43:e19)
Diagnosis
- These heterotopic lesions cannot be accurately diagnosed by imaging or endoscopic visualization due to lack of specific features, rendering histopathologic examination as the gold standard for precise diagnosis
Radiology description
- CT scan, fluoroscopy, capsule endoscopy and 99mTc pertechnetate scan can usually detect heterotopic gastric mucosa
- Capsule endoscopies have been shown to be superior compared with other radiological investigations, including barium contrast studies, computed tomographic enteroclysis, push enteroscopy and MRI
- Reference: Medicine (Baltimore) 2017;96:e5854
Radiology images
Images hosted on other servers:
33 year old man with HGM in ileum
12 year old girl with extensive HGM
Prognostic factors
- Patients with extensive heterotopia are at increased risk of adverse outcome, including massive hemorrhage or rarely death (Pediatr Dev Pathol 2000;3:277)
Case reports
- 33 year old man with heterotopic gastric mucosa in ileum (Case Rep Gastroenterol 2020;14:609)
- 38 year old woman with gastric heterotopia (Case Rep Gastroenterol 2015;9:233)
- 61 year old man with pancreatic and gastric heterotopia (Case Rep Gastrointest Med 2017;2017:3126108)
Treatment
- Surgery is the treatment of choice, whether it is carried out by laparoscopy or laparotomy
- Intraoperative gamma counter use has also been reported as a useful method of localizing bowel segments with nonpalpable areas of heterotopic gastric mucosa for resection (J Pediatr Surg 2001;36:1720)
Gross description
- Can present as a polypoidal lesion leading to intestinal obstruction, intussusception
Gross images
Case #124
Intraluminal polyp
Images hosted on other servers:
33 year old man with HGM in ileum
14 year old boy with HGM in ileum
Microscopic (histologic) description
- Lesions consist of full mucosal thickness of specialized gastric glands characterized by chief and parietal cells and surface lined by gastric foveolar epithelium
- Histologically, oxyntic mucosa may not be seen in all cases of gastric heterotopia
- Prevalence and risk of malignant transformation of heterotopic gastric mucosa are not entirely understood (J Pediatr Gastroenterol Nutr 2010;50:329)
- Some reports have described heterotopic gastric mucosa progressing to malignancy in the esophagus, gallbladder and rectum (Korean J Pathol 2013;47:289)
- Presence of H. pylori organism in heterotopic gastric mucosa in Meckel diverticulum is a rare histological finding; in the last 22 years, 12 published reports were found that specifically looked into the presence of H. pylori in a heterotopic gastric mucosa in a Meckel diverticulum (Clin Med Insights Case Rep 2019;12:1179547619846088)
Microscopic (histologic) images
Contributed by Khalid Amin, M.D.
Ileal polypoid lesion
Gastric glands
Jejunal polypoid lesion
Underlying antral glands
Molecular / cytogenetics description
- Altered expression of cell cycle molecules (the CIP / KIP family) can be associated with heterotopic gastric mucosa (Ann Gastroenterol 2013;26:184)
Sample pathology report
- Polyp, duodenum, polypectomy:
- Consistent with gastric heterotopic mucosa
Differential diagnosis
- Gastric metaplasia:
- Characterized by gastric foveolar epithelium and absence of specialized antral glands seen in heterotopic gastric mucosa
Board review style question #1
Which of the following statements about gastric heterotopia is true?
- Always a sequelae of chronic inflammation
- Can be associated with null mutation in CDX2 gene
- Microscopy shows gastric foveolar epithelium with absence of specialized gastric glands
- No malignant potential
Board review style answer #1
B. Can be associated with null mutation in CDX2 gene
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Reference: Heterotopic gastric mucosa
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Reference: Heterotopic gastric mucosa
Board review style question #2
Which organism can colonize heterotopic gastric mucosa?
- Crytosporidium
- Helicobacter pylori
- Tropheryma whipplei
- Trypansosoma cruzi
Board review style answer #2
B. Helicobacter pylori (Am J Gastroenterol 2003;98:1266)
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Reference: Heterotopic gastric mucosa
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