Barrett’s esophagus is a change in the normal lining of the esophagus (squamous mucosa) to a lining similar to the lining of the stomach (columnar mucosa) that is visible by endoscopy. In patients with Barrett’s esophagus, biopsy of the lining of the esophagus shows evidence of intestinal metaplasia: replacement of one cell type (squamous) with a different cell type (columnar).
Presence of cells called “goblet cells,” which are indicative of intestinal metaplasia in the biopsy specimen, is necessary to diagnose Barrett’s esophagus.
The condition develops when GERD damages the squamous lining of the esophagus and the injury heals through a process called metaplasia, in which columnar cells replace squamous ones.
Barrett’s esophagus is named after the British surgeon Norman Barrett, who in 1950 identified the changes in the lining of the esophagus, but thought they were congenital (present at birth). In 1970, it was shown that Barrett’s esophagus is an acquired condition (presents later in life). It is known that Barrett’s esophagus develops in approximately 5 to 8 percent of patients with gastroesophageal reflux disease.
With continued irritation of the metaplastic epithelium (lining of the esophagus) caused by gastroesophageal reflux disease, some patients will progress to further cellular damage. These changes happen in a sequence, and the damage to the cells progresses to low-grade dysplasia (abnormal cells), which then transform to high-grade dysplasia (precancerous cells), and finally to invasive adenocarcinoma, which can develop in approximately 0.5 percent per year in patients with Barrett's esophagus.
By Farzaneh Banki, M.D.
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