[Heterotopic gastric mucosa of the gastrointestinal tract]

Islets of heterotopic gastric mucosa can occur in the whole alimentary tract as well as in the gallbladder, the extrahepatic bile ducts and the pancreatic tissue. In most cases they have incidentally been discovered in autopsies and surgical specimens. Ectopic gastric mucosa is known to cause gastrointestinal bleeding in Meckel's diverticulum and duplications of the intestine, and, in exceptional cases may show a malignant transformation. In endoscopy of the gastrointestinal tract ectopic gastric epithelium can often be conjectured from certain morphological phenomena. In this paper we review pathogenesis, localization, clinical significance as well as diagnostic and therapeutic aspects of heterotopic gastric mucosa.