This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Tumors, Subject name: Orthopaedics
[{'content': "Codman triangle is seen in \nSelect and explain. \nA. Ewing's sarcoma, B. Osteosarcoma, C. Madura foot, D. All of the above", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Codman triangle is a term used to describe the triangular area of subperiosteal bone that is created when a lesion, often a tumor, raises the periosteum away from the bone. Plain X-ray * Irregular destruction in metaphysis. * New bone formation. * Periosteal reaction. * Sunray appearance or hair on end - tumor grows into the overlying soft tissue. * Codman&;s triangle - area off sub periosteal new bone formation seen at the area of tumor -host coex junction. REF : MAHESWARI 9TH ED', 'role': 'assistant'}]