This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': "Barrett's esophagus is characterised by which of the following histologic change? \nSelect and explain. \nA. Squamous metaplasia, B. Intestinal metaplasia, C. Squamous dysplasia, D. Intestinal dysplasia", 'role': 'user'}, {'content': "Answer: B \nExplanation: Barrett's esophagus is a condition in which squamous epithelium of the esophagus is replaced by metaplastic columnar epithelium containing goblet and columnar cells in some patients with GERD. Barrett's epithelium is a major risk factor for adenocarcinoma of the esophagus due to proximal displacement of the squamocolumnar junction. In patients with more than 10 year history of GERD should undergo a screening EGD for Barrett's esophagus. Endoscopic biopsy is the gold standard for confirmation of Barrett's esophagus, and for dysplasia or cancer arising in Barrett's mucosa. Ref: Harrison's Principles of Internal Medicine, 18e chapter 291.", 'role': 'assistant'}]