This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Osteogenic Sarcoma, Subject name: Orthopaedics
[{'content': "7 year old child presents with a lesion in upper tibia. X-ray shows radiolucent area with Codman's triangle and Sunray appearance. Diagnosis is : \nSelect and explain. \nA. Ewing's sarcoma, B. Osteosarcoma, C. Osteoid osteoma, D. Chondrosarcoma", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. is \'b\' i.e. Osteosarcoma Codman\'s triangle and sunray appearance is seen in both Osteosarcoma & Ewing\'s tumor, but the catch point is location of the tumor i.e. upper end of tibia.Osteosarcoma - most commonly involves long bone metaphyses, especially around the knee and at the proximal end of the humerus.Ewing\'s sarcoma - most commonly involves the mid-diaphyseal region (common bones are tibia, fibula clavicle etc.) [About age Apley\'s writes - "Osteosarcoma is said to occur predominantly in children and adolescents".For differential diagnosis of bone tumors see Q.no. 153 of Nov. 2001', 'role': 'assistant'}]