This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T., Subject name: Radiology
[{'content': 'On barium swallow Leiomyoma shows following characteristic appearance- \nSelect and explain. \nA. Rat tail appearance, B. Cork screw appearance, C. Oval mass lined by barium, D. String sign', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Oval mass lined by barium * On barium swallow, leiomyoma may be seen as a discrete round or ovoid submucosal mass that is well outlined by barium. Its borders form slightly obtuse angles with the oesophageal wall.* Oesophageal leiomyoma is a benign smooth-muscle neoplasm of the oesophagus. It is the most common benign tumor of the oesophagus.* They typically involve the mid-to-distal oesophagus.", 'role': 'assistant'}]