This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Breast Cancer - Types and Staging, Subject name: Surgery
Commonest type of ca breast is : 
Select and explain. 
A. Papillary ca, B. Pagets disease, C. Fibrasorcoma, D. Infiltrative ductal ca
D: Infiltrative ductal ca
Answer: D: Infiltrative ductal ca 
Explanation: Ans. is 'd' ie Infiltrative Ductal ca Almost all breast malignancies are adenocarcinomas, all other types (i.e. squamous cell Ca, phylloides tumors, sarcomas, and lymphomas are rareThey are divided into two types ductal and lobular types each of which are further two types carcinoma in situ & invasive type.Ductal carcinomas arise from epithelium lining the ducts and lobular arises from the epithelium of the acini forming lobules.Infiltrative ductal Ca is the most common type of breast Ca.