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': 'Single file pattern is seen in breast cancer type? \nSelect and explain. \nA. Intraductal, B. Infiltrating lobular, C. Infiltrating ductular, D. All', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. is \'b\' i.e. Infiltrating lobular "The hisological hallmark of lobular carcinomas is the pattern of single infiltrating tumor cells, often only one cell in width (in the form of a single file) or in loose clusters or sheets."', 'role': 'assistant'}]