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: Surgery
[{'content': 'A 10 year old boy was found to have a symmetric radiolytic lesion on the X-ray at the upper end of the right humerus after being admitted for fracture of humerus. Such a lesion is present on the left humerus as well. What is the likely pathology? \nSelect and explain. \nA. Unicameral bone cyst, B. Osteosarcoma, C. Osteoclastoma, D. Aneurysmal bone cyst', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The age of the child, symmetric radiolytic lesion on the upper end of the humerus on both sides with the history of fracture are suggestive of a case of unicameral bone cyst. Ref: Textbook of Disorders and Injuries of the Musculoskeletal System By Robe Bruce Salter, Pages 398-399 ; Essentials in Bone and Soft-Tissue Pathology By Edward F. McCahy, Jasvir S. Khurana, Paul J. Zhang, 2010, Page 70 ; Musculoskeletal Imaging: A Concise Multimodality Approach By Klaus Bohndorf, Herwig Imhof, Thomas Lee Pope, 2001, Page 162', 'role': 'assistant'}]