| Barrett's Esophagus Tutorial
Definition of Barrett’s Esophagus
The diagnosis of Barrett’s esophagus requires both endoscopic
and histologic evidence of metaplastic columnar epithelium.
Endoscopically, there must be columnar epithelium within the esophagus.
Histologically, the epithelium must be metaplastic, as defined by the
presence of goblet cells. An Alcian blue stain at pH 2.5 stains the acidic
mucin present in the goblet cells. The most common errors in the
identification of goblet cells are: 1) "pseudogoblet" cells; and 2) Alcian
blue positive cells that are not goblet cells.
cells are barrel-shaped gastric surface or foveolar cells that do not
stain with Alcian blue. These cells commonly have a blush of eosinophilia,
due to neutral mucin, on H&E stained sections, in contrast to the
blush of basophilia, imparted by the acidic mucin in goblet cells.
Alcian blue positivity in a columnar cell does not necessarily indicate
a metaplastic goblet cell; it should have a barrel shape. Other types of
cells that can be alcian blue positive but which lack the barrel shape
include: reactive gastric
foveolar cells, which may be present in the pits and on the mucosal
surface, mucous neck cells
of the gastric glands, esophageal cardiac glands, and submucosal
glands in the esophagus.
As stated above, the diagnosis of Barrett’s esophagus requires both
endoscopic and histologic evidence of metaplastic columnar epithelium. The
significance of metaplastic columnar epithelium in a biopsy of the GE
junction region when the endoscopist has not seen columnar epithelium
within the esophagus has not been established.