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Barrett's Esophagus

Barrett's esophagus

For medical students2 min readUpdated 2026-10-10

Barrett's esophagus is an acquired pathological condition characterized by epithelial metaplasia of the esophageal mucosa. The pathology features the replacement of stratified squamous epithelium with glandular epithelium, forming areas of specialized intestinal metaplasia proximal to the Z-line.

Main MarkerFoci of intestinal metaplasia and the presence of goblet cells
Macroscopic AppearanceEpithelial patches resembling 'flame-like tongues' proximal to the Z-line
Main RiskHigh probability of malignant transformation and adenocarcinoma development
Molecular FactorsOverexpression of Bcl-2, Rab11, telomerase activation, and COX-2

Definition and Endoscopic Criteria

This condition represents an acquired zone of epithelial metaplasia. The pathological lesion is located circumferentially above the lower boundary of the esophagogastric junction, known as the Z-line, and extends proximally for three centimeters or more.

During endoscopic evaluation, patches of altered glandular epithelium have a distinctive red color and stand out sharply against the pale, pinkish, unaltered stratified squamous epithelium of the esophagus. Visually, these areas resemble 'flame-like tongues'.

Histological Appearance and Origin

Microscopic examination reveals a combination of two epithelial types: gastric-type glandular epithelium adjacent to normal squamous epithelium. The key diagnostic feature is intestinal metaplasia, accompanied by cytological markers—goblet cells.

The source stem cells driving differentiation are thought to be multipotent cells of the squamous basal layer or elements located within the excretory ducts of cardiac glands. Chronic inflammation alters the microenvironment, which begins to regulate the proliferation and differentiation of stem cells toward metaplasia.

Pathogenesis of Malignancy and Molecular Stages

The most dangerous variant of the clinical course is incomplete intestinal metaplasia with active secretion of sulfomucins, which stain black with iron diamine and alcian blue. Malignancy is driven by the following processes:

  1. Genetic instability: chromosomal aberrations, mutations, and loss of heterozygosity of alleles (DCC, APC), as well as inactivation of tumor suppressor genes (CDKN2, p53).
  2. Epimutations: reversible shifts in the activity of genes controlling cell division.
  3. Biochemical shifts: overexpression of the anti-apoptotic protein Bcl-2 and the Rab11 protein, which transmits proliferative signals.
  4. Enzyme activation: induction of telomerase, which promotes cellular immortalization, as well as nitric oxide synthase and cyclooxygenase-2 (COX-2).

As a result of accumulated genetic defects and suppressed apoptosis, esophageal adenocarcinoma develops.

Mnemonic

Barrett's means 'flame-like tongues' of intestinal metaplasia with goblet cells, leading to adenocarcinoma.

Frequently asked questions

What types of metaplasia occur in Barrett's esophagus besides intestinal?

In addition to intestinal metaplasia, gastric-type metaplasia can occur in Barrett's esophagus. The disease pathogenesis follows a strict sequence: against the background of chronic esophagitis, patches of specialized gastric epithelium initially appear. Only subsequently does intestinal epithelium with goblet cells develop, the presence of which is a mandatory histological criterion for this precancerous condition. Gastic-type glandular epithelium lies adjacent to the normal stratified squamous epithelium of the esophagus.

How is Barrett's esophagus classified based on the length of the affected segment?

Barrett's esophagus is diagnosed during upper endoscopy and evaluated using the Prague classification. According to standard criteria, the zone of epithelial metaplasia lies circumferentially above the lower boundary of the esophagogastric junction (Z-line) and extends proximally for 3 cm or more. Patches of metaplastic epithelium are visualized as 'flame-like tongues' located above the Z-line, contrasting sharply with the pale pink, unaffected stratified squamous esophageal epithelium.

What diseases and risk factors are the primary causes of Barrett's esophagus?

Barrett's esophagus is described as a complication of GERD and a condition associated with chronic esophagitis. Prolonged exposure of the esophageal mucosa to gastroesophageal refluxate induces inflammatory, dystrophic, erosive-ulcerative, and metaplastic changes in the stratified squamous epithelium. Chronic inflammation alters the microenvironment, which in turn regulates stem cell proliferation and differentiation toward metaplasia.

Risk factors for Barrett's esophagus include:

  • prolonged history of GERD;
  • male sex;
  • obesity;
  • age over 50 years.
What are the primary endoscopic and histological features of Barrett's esophagus?

Endoscopically, red patches resembling 'flame-like tongues' extending proximally from the Z-line by 3 cm or more are observed. Histologically, intestinal metaplasia with the mandatory presence of goblet cells is identified.

Why is Barrett's esophagus considered a precancerous condition?

The condition is associated with a high risk of developing adenocarcinoma. Pathogenesis involves genetic instability, tumor suppressor mutations, telomerase activation, and suppression of apoptosis in the setting of incomplete intestinal metaplasia.

What staining methods are used to diagnose specialized epithelium?

Standard hematoxylin and eosin (H&E) staining is used to assess tissue architecture, alongside iron diamine combined with alcian blue to detect sulfomucins in goblet and columnar cells.

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