This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Orthopaedics
APatient has history of A 2 years back, at the same sight he developed pain and swelling. Xray shows the following features . What will be the diagnosis? 
Select and explain. 
A. Osteogenic sarcoma, B. Ewing's sarcoma, C. Chronic osteomyelitis, D. Multiple myeloma
C: Chronic osteomyelitis
Answer: C: Chronic osteomyelitis 
Explanation: Garre sclerosing osteomyelitis, or chronic nonsuppurative sclerosing osteomyelitis, is a form of chronic osteomyelitis. Mild inflammation and infection lead to subperiosteal bone deposition. The disease is frequently asymptomatic. The characteristic radiographic appearance is an area of periosteal proliferation surrounded by successive layers of condensed coical bone (arrows), described as an onion skin appearance. REF : MAHESHWARI BOOK 9TH ED