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
Commonest cause of blood discharge from the nipple is 
Select and explain. 
A. Duct carcinoma, B. Duct papilloma, C. Chronic cystic mastitis, D. Cystosarcoma phyllodes
B: Duct papilloma
Answer: B: Duct papilloma 
Explanation: Duct papilloma is the Commonest cause of blood discharge from the nipple Duct papilloma are epithelium lined true polyps of breast lactiferous ducts it is usually single,from a single lactiferous duct it blocks the duct causing ductal dialatation ref ;(page no;528) 5th edition of SRB&;S Manual of SURGERY