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': 'A mature, encapsulated collection of pancreatic and/or peripancreatic necrosis that has developed a well defined inflammatory wall is best known as: \nSelect and explain. \nA. WOPN (walled-off Pancreatic necrosis), B. Pseudocyst, C. Pancreatic abscess, D. Cystic neoplasm of pancreas', 'role': 'user'}, {'content': 'Answer: A \nExplanation: WOPN (walled-off pancreatic necrosis) A mature, encapsulated collection of pancreatic and/or peripancreatic necrosis with a well defined inflammatory wall. WOPN usually occurs >4 weeks after onset of necrotising pancreatitis. CECT criteria Heterogeneous with liquid and non-liquid density with varying degrees of loculations Well defined wall, that is, completely encapsulated Ref:Gut 2013;62:102-111. doi:10.1136/gutjnl-2012-302779.', 'role': 'assistant'}]