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
Most common cause of unilateral parotid swelling in a 27 yr old male is: 
Select and explain. 
A. Wahins tumor, B. Pleomorphic adenoma, C. Adenocarcinoma, D. Haemangioma
B: Pleomorphic adenoma
Answer: B: Pleomorphic adenoma 
Explanation: They are the commonest tumors of the parotid gland & account for 60% of tumors in the Parotid. Ref: Robbin's Basic Pathology, 5th Edition, Page 750; Bailey and Love's Sho Practice of Surgery, 22nd Edition, Page 475 and 23rd Edition, Page 659; CSDT, 11th Edition, Page 294.