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: Pathology
True about histology in infilterating lobular breast carcinoma - 
Select and explain. 
A. Single file pattern, B. Pleomorphic cells in sheets, C. Cribriform pattern, D. Pin wheel pattern
A: Single file pattern
Answer: A: Single file pattern 
Explanation: Histological hallmark of invasive lobular breast carcinoma is pattern of single infilterating tumor cells often only one cell in width or in loose clusters or sheets.