This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
[{'content': 'A 2 year old boy suffering from leukemia, following are the x–ray findings –a) Osteolytic lesion in flat bonesb) Metaphyseal osteoporosisc) Periosteal new bone formationd) Osteosclerosis of long bonese) Transverse line of dark band below the growth plate \nSelect and explain. \nA. ab, B. bce, C. acd, D. ace', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Characteristically, there are zones of rarefaction with delicate subperiosteal new bone formation in the metaphysial regions of femur, humerus or spine and pelvis.\nX-ray reveals subepriosteal and subepiphyseal resorption of bones.\nDark bands above the metaphysis called Growth Arrest Lines.\nMetaphyseal lucencies affects maximum growth.\nOsteolytic lesions seen in half of the cases and is commonest in shaft of long bones.\nOsteoblastic lesions are rare, occur in metaphysis.\nALL may show following features on X-ray.\n\n\nPeriosteal Reaction\nMetaphyseal cortical erosions\nAltered medullary trabeculations, subepiphyseal bone resorption.', 'role': 'assistant'}]