Key Points

Columnar-lined esophagus, or Barrett’s esophagus (BE), is an acquired condition secondary to gastroesophageal reflux disease (GERD) in which the normal stratified squamous epithelium lining the distal esophagus is replaced to a variable extent by metaplastic columnar epithelium containing goblet cells, also known as specialized intestinal metaplasia (SIM). The term long-segment BE (LSBE) refers to SIM extending more than 3 cm above the esophagogastric junction. Patients with less than 3 cm of endoscopically evident columnar-appearing mucosa, often as tongues, containing SIM are labeled as having short-segment BE (SSBE). This definition distinguishes SSBE from intestinal metaplasia found just below a normally located squamocolumnar junction, which is termed intestinal metaplasia of the cardia.[1],[2] Investigators recommend maintaining the distinction between endoscopically apparent long segments (>3 cm) and short segments (< 3 cm) of SIM because most of our current knowledge of the pathophysiology, incidence, prevalence, and risk of malignant transformation of BE has come from studies of patients with LSBE (Figure 1). Indeed, the definition of BE has changed over time, and earlier definitions had restricted BE to SIM that was 3 cm or more above the esophagogastric junction. BE and GERD are the major recognized risk factors for esophageal adenocarcinoma, a tumor whose frequency has increased profoundly in Western countries over the past several decades.[3]

Figure 1 

Endoscopic images of columnar epithelium (A) in the distal esophagus extending more than 3 cm above the esophagogastric junction (LSBE) or (B) in the form of a single tongue (SSBE) 1 cm in length. C, Microscopic section of Barrett’s epithelium. Note the villiform surface of Barrett’s epithelium and the characteristic presence of goblet cells (dark blue).