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: Pathology
Histology of Myositis ossificans mimics - 
Select and explain. 
A. Osteosarcoma, B. Osteochondroma, C. GCT, D. Ewing's tumour
A: Osteosarcoma
Answer: A: Osteosarcoma 
Explanation: Histologically myositis ossificans mimics osteosarcoma.
They can be differentiated by zone phenomenon :-

Osteogenic sarcoma → Central zone contains mature cells and peripheral zone contains more active immature cells.
Myositis ossificans → Central zone contains active immature cells and peripheral zone contains more mature cells.