What is Barrett's esophagus?Barrett's esophagus is a complication ofchronic gastroesophageal reflux disease (GERD), primarily in white men.
What is Barrett's esophagus?
Barrett's esophagus is a complication of chronic gastroesophageal reflux disease (GERD), primarily in white men. GERD is a disease in which there is reflux of acidic fluid from the stomach into the esophagus (the swallowing tube). It most commonly causes heartburn.
There are two requirements for the diagnosis of Barrett's esophagus. The requirements necessitate an endoscopy of the esophagus. During endoscopy, a long flexible tube with a light and camera at its tip (an endoscope) is inserted through the mouth and into the esophagus to view and biopsy (sample tissue from) the lining of the esophagus. The two requirements are:
At endoscopy, an abnormal pink lining should be seen as replacing the normal whitish lining of the esophagus. This abnormal lining extends a short distance (usually less than 2.5 inches) up the esophagus from the gastroesophageal junction (the GE junction, which is where the esophagus joins the stomach).
Microscopic evaluation of the biopsy of this abnormal lining should shows that the normal lining cells of the esophagus have been replaced by intestinal type lining cells, including mucus-producing cells called goblet cells. Other cells also are present, some of which resemble cells that line the stomach. However, if intestinal goblet cells are not present, the diagnosis of Barrett's esophagus should not be made.
Barrett's esophagus is officially coded by the Library of Congress for electronic searches of the literature as Barrett esophagus, but Barrett's esophagus (with the apostrophe "s") is the name used universally. The condition is named after a surgeon, Norman Barrett, who described the condition. However, it turns out that his interpretation of the findings was not correct. In 1953, Doctors' Allison and Johnstone actually described this condition as we now understand it, namely that metaplasia was occurring. (Metaplasia, which is discussed below, is the term used when one adult tissue replaces another.) Nevertheless, the condition has been immortalized with Barrett's name.
Initially, it was thought that the Barrett's esophagus consisted of stomach (gastric) tissue replacing the usual squamous tissue lining the esophagus. However, in the mid 70's, Dr. Paull and colleagues published a paper in which they described the mucosa (inner lining) of Barrett's esophagus in greater detail than had been done previously. They pointed out that Barrett's esophagus consisted of a metaplasia in which the normal cells lining the esophagus were replaced by a mixture of gastric and intestinal lining cells. The intestinal-type lining cells also are called specialized columnar cells which include goblet cells. For a number of years, some scientists thought that there were two types of Barrett's; one in which the normal lining was replaced with stomach (gastric) type cells only, and the second in which intestinal cells were present. However, the current belief is that only the presence of intestinal-type goblet cells establishes the diagnosis of Barrett's esophagus, regardless of what other cell types are present.
Why is there so much interest in Barrett's esophagus?
The reason for the great interest in Barrett's esophagus is that it is associated with an increased risk of cancer of the esophagus. The type of cancer that occurs in patients with Barrett's is adenocarcinoma, which arises from the metaplastic intestinal tissue. The usual cancer of the esophagus that is not associated with Barrett's is squamous carcinoma, which arises from the squamous cells lining that is normally present in the esophagus. The connection between adenocarcinoma of the esophagus and Barrett's esophagus is now clear, and adenocarcinoma of the esophagus is increasing in frequency in most countries in the Western hemisphere.
The good news, however, is that the cancer occurs in relatively few patients with Barrett's esophagus. Still, the main challenge in this condition is to watch for early warning signs of cancer by taking biopsies at regular intervals during endoscopy. This practice is called surveillance and is similar, in principle, to the surveillance in women for cancer of the cervix, wherein PAP smears are taken at regular intervals.