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: Orthopaedics
[{'content': "A 33-year-old man presented with a slowly progressive swelling in the middle 1/3' of his right tibia. X-rays examination revealed multiple sharply demarcated radiolucent lesions separated by areas of dense and sclerotic bone. Microscopic examination of a biopsy specimen revealed island of epithelial cells in a fibrous stroma. Which of the following is the most probable diagnosis? \nSelect and explain. \nA. Adamantinoma, B. Osteofibrous dysplasia, C. Osteosarcoma, D. Fibrous cortical defect", 'role': 'user'}, {'content': 'Answer: A \nExplanation: The characteristic radiological and microscopic features, together with other clinical features suggests the diagnosis of Adamantinoma.\nX-ray features ofAdamantinoma\nMultiple sharply demarcated radioluscent lesions in the diaphysis of tibia. There radioluscent lesions are separated by areas of dense sclerotic bone.\nMicroscopic feature — Islands of epithelial cells are present in fibrous stroma.', 'role': 'assistant'}]