Barrett's esophagus and adenocarcinoma of the gastroesophageal junction: a pathologic perspective.

Barrett's esophagus is defined clinically by the presence of endoscopically evident columnar mucosa in the distal esophagus with histopathologic confirmation of the presence of intestinal-type epithelium. The etiology of Barrett's esophagus is understood poorly, but chronic gastroesophageal reflux disease is considered a major contributing factor. Barrett's esophagus is associated with the development of adenocarcinoma of the gastroesophageal junction. It is believed that the development of a Barrett-type mucosa with intestinal goblet-type cells is due to an altered process of differentiation of pluripotent epithelial stem cells in response to the local injury and repair process. The potential identification and isolation of markers for screening purposes and possibly prognostic information are areas of considerable clinical and scientific interest.