Gastrin-producing cells in ectopic gastric mucosa of developmental and metaplastic origins.

Immunocytochemical techniques using antigastrin antibody were employed to localize G cells in ectopic gastric mucosa of metaplastic and congenital origins and to compare their distribution with that in normal gastric mucosa. Five examples of Barrett's esophagus, 8 Meckel's diverticula, and 2 small bowel duplications were studied. Although G cells were absent in the gastric mucosa from all cases of Barett's esophagus, four Meckel's diverticula and one small bowel duplication contained G cells. In all instances of congenitally derived ectopic gastric mucosa where G cells were demonstrable, the gastric mucosa showed areas of antropyloric differentiation, whereas in the remaining cases the ectopic gastric mucosa was exclusively of the body-fundic type. It is concluded that the presence of G cells within ectopic gastric mucosa of Meckel's diverticula and small bowel duplications in foci of antropyloric differentiation reflects their developmental origin, whereas the absence of G cells in Barrett's esophagus is in keeping with its metaplastic derivation.