This definition appears rarely
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.