This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology and breast, Subject name: Surgery
Which of the following test is unable to differentiate between &;in situ&; breast cancer and invasive disease 
Select and explain. 
A. Core needly biopsy, B. FNAC, C. Excisional biopsy, D. None
B: FNAC
Answer: B: FNAC 
Explanation: Management of DCIS : FNAC confirms the disease but will not differentiate DCIS from invasive carcinoma. Ref : SRB&;s 4thE pg: 566