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
All of the following are significant risk factors for colonic carcinoma in an adenomatous polyp except 
Select and explain. 
A. Pedunculated polyp, B. Villous histology, C. Size > 2 cm, D. Atypia
A: Pedunculated polyp
Answer: A: Pedunculated polyp 
Explanation: Adenomatous polyps may be sessile or pedunculated. Cancers develop more frequently in sessile polyps.
Atypia, on histology, seen anywhere, is a risk factor for cancer.