What is Barrett's esophagus?
Barrett’s esophagus is a change in the lining of the esophagus caused by chronic reflux of stomach and duodenal contents into the esophagus. Barrett's esophagus is a condition that develops in some people who have chronic gastroesophageal reflux disease (GERD) or inflammation of the esophagus (esophagitis). In Barrett's esophagus, the normal cells that line the esophagus, called squamous cells, turn into a type of cell not usually found in humans, called specialized columnar cells.
Damage to the lining of the esophagus -- for example, by acid reflux from GERD -- causes these abnormal changes.
Barrett's esophagus is uncommon. Only a small percentage of people with GERD develop Barrett's. But once it's diagnosed, there's a much greater risk of developing esophageal cancer, which often spreads from the esophagus to lymph nodes and to other organs. Although increased, the absolute risk of esophageal cancer for someone with Barrett's esophagus is small — less than one percent a year.
The esophagus is a muscular tube that extends from the neck to the abdomen and connects the back of the throat to the stomach. Its inner lining, or mucosa, normally consists of flat cells (known as squamous cells) which are similar to those of the skin. When this squamous cell lining is replaced by other cells that have a more cube-like shape, the condition is known as Barrett's esophagus or the columnar-lined esophagus, referring to cells that are shaped like a column. When Barrett's esophagus is present, the columnar lining extends from the junction of the esophagus and stomach upwards into the esophagus for a variable distance ranging from a few centimeters to nearly the entire length of the esophagus.
When the normal squamous lining cells of the esophagus are replaced by columnar cells, the process is known as metaplasia. Barrett's esophagus is a form of metaplasia. The metaplastic columnar lining comes in three types. Two types are similar to groups of cells found in regions of the stomach lining. The third type is similar to groups of cells found in the small intestine. This intestinal type of metaplasia is important because it can potentially lead to the development of cancer.