This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bone Tumour, Subject name: Orthopaedics
[{'content': 'Commonest bone tumour is \nSelect and explain. \nA. Osteoid osteoma, B. Compact osteoma, C. Osteoblastoma, D. Solitary bone cyst', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A. i.e. (Osteoid ostoma) (312 - Current diagnosis and Treatment 4th)OSTEOID OSTEOMA* Most common benign osteoid- forming tumor is the osteoid osteoma* More common in male (second decade)* Proximal femur is the most common site*** Dull aching pain is the most frequent symptom* Characteristic x-ray finding - central lytic nidus* The non ossifying fibroma of bone is the most commn benign tumor of bone and the solitary osteochondroma is the second most common (315- Current diagnosis & Treatment - orthopedics)* Simple bone cysts are a common pseudotumor of bone and the most frequent cause ofpathologic fractures in children (320 CDT - orthopaedics 4th)', 'role': 'assistant'}]