This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Childhood Tumors, Subject name: Pediatrics
[{'content': 'Intussusception is caused by: \nSelect and explain. \nA. Submucous lipoma, B. Subfascial lipoma, C. Subserous lipoma, D. Intramural lipoma', 'role': 'user'}, {'content': "Answer: A \nExplanation: a. Submucous lipoma(Ref: Nelson's 20/e p 1812-1814, Ghai 8/e p 287)Predisposing conditionsPeyer's patches or prominent mounds of lymph tissue lead to mucosal prolapse of ileum into colon;Other lead points: Meckel diverticulum, intestinal polyp, neurofibroma, intestinal duplication cysts, hamartomas, ectopic pancreatic tissue, hemangioma, lipomaClinical featuresSudden onset of severe paroxysmal colicky pain in a previously well child, that recurs frequently60% infants pass a stool containing red blood and mucus, the currant jelly stoolVomiting occurs in most cases and is usually more frequently in the early phase.", 'role': 'assistant'}]