Which radiographic feature is classically associated with osteosarcoma?

Which radiographic feature is classically associated with osteosarcoma?

• A. Sunray appearance
• B. Onion-skin periosteal reaction
• C. Codman triangle
• D. Moth-eaten lytic pattern

Answer: (A)

Osteosarcoma often drives rapid production of osteoid by malignant osteoblasts, which lifts the periosteum and lays down new bone in radiating spicules perpendicular to the cortex. On X-ray this creates the sunburst (sunray) appearance, with rays extending outward from the involved bone. This pattern is the most characteristic radiographic sign of osteosarcoma. Other aggressive lesions can show different periosteal reactions—onion-skin (layered), Codman triangle (subperiosteal triangle), or a moth-eaten lytic pattern—but the distinct sunray configuration remains the hallmark for this tumor.