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
Vertebra plana occurs in 
Select and explain. 
A. Eosinophilic granuloma, B. Chondrosarcoma, C. Osteosarcoma, D. Fibrosarcoma
A: Eosinophilic granuloma
Answer: A: Eosinophilic granuloma 
Explanation: (Eosinophilic granuloma) (182-83-A) (226-CDT-orthopedics 4th)Eosinophilic-granuloma and Histiocytosis - X ray shows a well demarcated oval area of radiolucency within the bone, sometimes this is associated with marked reactive sclerosis. There may be multiple lesions and in the skull they have characteristic punched out - appearance.* Vertebral collapse may result in a flat wedge (vertebra plana) which is pathognomonic and "coin-on-end" appearance* Eosinophilic granuloma usually resolves spontaneously* The use of anterior decompression and anterior fusion is the treatment of choice in patients with neurologic symptoms