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': 'Ewings sarcoma clinically mimics - \nSelect and explain. \nA. Osteomyelitis, B. Osteochondroses, C. Osteosclerosis, D. Heterotopic ossification', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Osteomyelitis o Ewing sarcoma is one of the differential diagnosis for subacute osteomyelitis, ( see following table) TypeGledhill classificationRobert et at ClassificationDifferential diagnosisISolitary' localized zone of radioluceney surrounded by reactive new bone formationIa-Punched-out radioluceney Ib-Punched-out radiolucent lesion with sclerotic marginLangerhans cell histiocytosis Brodie abscessIIMetaphyseal radiolucencies with cortical erosion Eosinophilic granuloma; osteogenic sarcomaIIICortical hyperostosis in diaphysis; no onion skinningLocalized cortical periosteal reactionOsteoid osteomaIVSubperiosteal new bone and onion skin layeringOnion skin periosteal reactionEwing sarcomaV Central radioluceney in epiphysisChondroblastomaVI Destructive process involving vertebral bodyTuberculosis; osteogenic sarcoma", 'role': 'assistant'}]