<prompt> Characteristic of Barretts esophagus is?Increased risk of SCCColumnar MetaplasiaMost commonly in middle one third of esophagusGastric metaplasia is most common  <response>: Ans. is b i.e. Columnar metaplasia Barretts esophagus is a metaplasia in which normal squamous epithelium of lower part of esophagus is replaced by columnar epithelium due to prolonged esophageal reflux. Most common type of metaplasia in Barretts esophagus is intestinal metaplasia which is characterized by presence of intestinal goblet cells in the metaplastic columnar epithelium. Barretts esophagus is a pre-malignant condition. It is the single most important risk factor for adenocarcinoma of esophagus. 