This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gastrointestinal Radiology, Subject name: Radiology
Bowler hat sign is seen in 
Select and explain. 
A. Sigmoid volvulus, B. Midgut volvulus, C. Intussusception, D. Sessile colonic polyp
D: Sessile colonic polyp
Answer: D: Sessile colonic polyp 
Explanation: BOWLER HAT SIGN: Cup shaped filled defect seen on air contrast barium enema that represents POLYP if it points towards lumen. The "bowler-hat sign" represents the appearance of a sessile colonic polyp observed at an oblique angle on a double contrast barium enema. The bowler-hat sign is formed by a ring of barium adjacent to the base of the polyp surrounding a domed layer of barium coating the surface of the polyp.