Barrett's esophagus (British English: Barrett's oesophagus), sometimes called Barrett's syndrome or columnar epithelium lined lower oesophagus (CELLO), refers to an abnormal change (metaplasia) in the cells of the inferior portion of the esophagus. A positive diagnosis generally requires observing specific macroscopic and microscopic changes. The normal squamous epithelium lining of the esophagus is replaced by metaplastic columnar epithelium. Columnar epithelium refers to a cell type that is typically found in more distal parts of the gastrointestinal system. The medical significance of Barrett’s esophagus is its strong association with esophageal adenocarcinoma, a particularly lethal cancer.
The main cause of Barrett's esophagus is thought to be an adaptation to chronic acid exposure from reflux esophagitis. In the last 40 years, the incidence of esophageal adenocarcinoma has been increasing in the Western world. Barrett's esophagus is found in 5–15% of patients who seek medical care for heartburn (gastroesophageal reflux disease, GERD), although a large subgroup of patients with Barrett's esophagus do not have symptoms. It is considered to be a premalignant condition because it is associated with an increased risk of esophageal cancer (more specifically, adenocarcinoma) of about 0.5% per patient-year. Diagnosis of Barrett's esophagus requires endoscopy (more specifically, esophagogastroduodenoscopy, a procedure in which a small camera is inserted through the mouth to examine the esophagus, stomach, and duodenum) and biopsy. The cells of Barrett's esophagus, after biopsy, are classified into four general categories: non-dysplastic, low-grade dysplasia, high-grade dysplasia, and frank carcinoma. High-grade dysplasia and frank carcinoma patients are generally advised to undergo surgical treatment. Non-dysplastic and low-grade patients are generally advised to undergo annual observation with endoscopy. In high-grade dysplasia, the risk of developing cancer might be at 10% per patient-year or greater.
The condition is named after Norman Barrett (1903–1979) who described the condition in 1950.