Which radiographic feature is a buzz word for Ewing sarcoma?

Which radiographic feature is a buzz word for Ewing sarcoma?

• A. Parallel
• B. Spiculated
• C. Onion-skin periosteal reaction
• D. Hair on end

Answer: (D)

The main concept is recognizing how Ewing sarcoma appears on radiographs through aggressive periosteal reactions. The phrase hair on end describes vertically oriented, perpendicular periosteal bone formation that radiates from the cortex, giving a hair-like appearance on the film. This pattern is a memorable way to picture the rapid, aggressive periosteal response seen with Ewing, which is why it’s the buzz word highlighted here. While onion-skin periosteal reaction is also classically linked to Ewing, hair-on-end specifically emphasizes those radiating, hair-like spicules that some teaching materials use to label an aggressive periosteal reaction. In contrast, spiculated (sunburst) patterns point more toward osteosarcoma, and parallel isn’t a characteristic periosteal pattern associated with this tumor.