Barrett's Esophagus
Medical Author: Wilfred M. Weinstein, M.D.
Medical Editor:
Leslie J. Schoenfield, M.D., Ph.D.
What is Barrett's esophagus?
Barrett's esophagus occurs as a complication of chronic gastroesophageal
reflux disease (GERD), primarily in white males. GERD refers to the reflux of
acidic fluid from the stomach into the esophagus (the swallowing tube), and is
classically associated with heartburn.
There are two requirements for the diagnosis of Barrett's esophagus. To
meet these requirements, an endoscopy of the esophagus must be done. In this
procedure, a tube is inserted through the mouth and down the esophagus to view
and biopsy the lining of the esophagus. The two requirements are:
- During endoscopy of the lower esophagus, an abnormal
pink lining is seen as replacing the normal whitish lining of the esophagus.
This abnormal lining is seen to extend 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).
- Biopsy (tissue sampling) of this abnormal lining shows (under the
microscope) the presence of intestinal type cells that are called goblet cells,
because of their shape. Other cells are also present, some of which resemble
stomach cells. However, if intestinal goblet cells are not present, then 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, Drs.
Allison and Johnstone actually described this condition along the lines we now
understand, namely that a 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 lining of 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 lining of the esophagus was
replaced with a mixture of gastric and intestinal lining cells. The
intestinal-type lining cells are also called specialized columnar 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. In 1978, a paper
was published showing a strong association between cancer of the esophagus and
Barrett's esophagus in a small group of patients. The type of cancer that
occurs in patients with Barrett's is adenocarcinoma, which arises from the
intestinal metaplasia. The usual cancer of the esophagus is squamous-type
carcinoma, which arises from the squamous lining that is normally present in the
esophagus. The connection between adenocarcinoma of the esophagus and Barrett's
esophagus is now clear. In fact, this type of tumor 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 in these patients by taking biopsies at
endoscopies at regular intervals. 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.
Next: What causes Barrett's esophagus? »
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