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: Medicine
Adenocarcinoma of esophagus is commonly found in 
Select and explain. 
A. Achlasia acardia, B. Barret's oesophagus, C. Plummer vinson syndrome, D. Chronic smoking
B: Barret's oesophagus
Answer: B: Barret's oesophagus 
Explanation: Answer is B (Barret's esophagus) Adenocarcinoma is seen in Barret's esophagus Barret's esophagus is a metaplastic change in the lining mucosa of oesophagus in response to chronic gastroesophagus reflex. In Barret's esophagus the junction between oesophageal mucosa (squammous) and gastric mucosa (columnar) moves proximally such that the lower pa of esophagus now becomes lined with different types of gastric mucosa. This pa of oesophagus has an increased risk for adenocarcinoma i.e. Adenocarcinoma is seen in Barrets esophagus.