X-ray shows an onion skin appearance is most characteristic of which tumor?

X-ray shows an onion skin appearance is most characteristic of which tumor?

• A. Ewing Sarcoma
• B. Osteosarcoma
• C. Chondrosarcoma
• D. Rhabdomyosarcoma

Answer: (A)

Onion-skin periosteal reaction on X-ray is a classic radiographic pattern seen with an aggressive bone tumor, most strongly linked to Ewing sarcoma. The layered, concentric periosteal new bone forms as the tumor rapidly grows and repeatedly raises the periosteum, creating that characteristic onion-like appearance. Ewing tends to affect children and adolescents and often involves the diaphysis of long bones, which fits the typical location of this finding. Other tumors have different radiographic cues: osteosarcoma commonly shows a sunburst pattern with Codman triangle, chondrosarcoma presents with calcified cartilaginous matrix and endosteal changes, and rhabdomyosarcoma is primarily a soft-tissue malignancy with less specific bone reaction. So the onion-skin appearance is most characteristic of Ewing sarcoma.

Onion-skin periosteal reaction on X-ray is a classic radiographic pattern seen with an aggressive bone tumor, most strongly linked to Ewing sarcoma. The layered, concentric periosteal new bone forms as the tumor rapidly grows and repeatedly raises the periosteum, creating that characteristic onion-like appearance. Ewing tends to affect children and adolescents and often involves the diaphysis of long bones, which fits the typical location of this finding. Other tumors have different radiographic cues: osteosarcoma commonly shows a sunburst pattern with Codman triangle, chondrosarcoma presents with calcified cartilaginous matrix and endosteal changes, and rhabdomyosarcoma is primarily a soft-tissue malignancy with less specific bone reaction. So the onion-skin appearance is most characteristic of Ewing sarcoma.