The onion skin-like periosteal reaction is mainly due to the subperiosteal osteophytes after the periosteum has been stimulated. Due to repeated stimulation or persistence of the cause, subperiosteal osteogenesis will soon form multilayered osteophytes, which will be found on the X-ray as homocentric lamellar osteophytes wrapped around the bone, called onion skin-like periosteal reaction. Common causes include infection, trauma, fracture, fatigue fracture, tumor, and other factors that stimulate laminar hyperplasia of the periosteum, resulting in onionskin-like reaction of the periosteum. Onion skin reaction is not unique to bone tumors, other diseases may also have periosteal reaction, but tumors are often accompanied by periosteal reaction.