Question:medium
What is the most likely diagnosis for the lesion shown here?
What is the most likely diagnosis for the lesion shown here?
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Spicules radiating perpendicular to the cortex (sunburst) with a Codman triangle point to the commonest malignant bone tumour of young people.
Updated On: Jun 22, 2026
- Osteosarcoma
- Ewing sarcoma
- Chondrosarcoma
- Osteoclastoma (giant cell tumour)
Show Solution
The Correct Option is A
Solution and Explanation
Work backwards from the radiological sign to the tumour.
The sign: The picture shows bone spicules fanning outward at right angles to the shaft - the "sunburst" or sun-ray appearance - produced when an aggressive tumour pushes through the cortex and the periosteum lays down reactive bone along stretched fibres. A raised cuff of periosteum at the lesion edge (Codman triangle) often accompanies it.
Matching it to a tumour: The sunburst reaction plus Codman triangle is the textbook signature of osteosarcoma, the most common primary malignant bone tumour of adolescents, favouring the metaphysis near the knee (distal femur/proximal tibia).
Pattern recognition for the rest:
$\bullet$ Onion-skin (laminated) periosteum in a diaphysis $\rightarrow$ Ewing sarcoma.
$\bullet$ Lytic lesion with rings-and-arcs / popcorn calcification $\rightarrow$ chondrosarcoma.
$\bullet$ Eccentric expansile soap-bubble lytic lesion at the epiphysis of a fused bone $\rightarrow$ giant cell tumour (osteoclastoma).
Conclusion: A sunburst lesion = osteosarcoma (option A).
The sign: The picture shows bone spicules fanning outward at right angles to the shaft - the "sunburst" or sun-ray appearance - produced when an aggressive tumour pushes through the cortex and the periosteum lays down reactive bone along stretched fibres. A raised cuff of periosteum at the lesion edge (Codman triangle) often accompanies it.
Matching it to a tumour: The sunburst reaction plus Codman triangle is the textbook signature of osteosarcoma, the most common primary malignant bone tumour of adolescents, favouring the metaphysis near the knee (distal femur/proximal tibia).
Pattern recognition for the rest:
$\bullet$ Onion-skin (laminated) periosteum in a diaphysis $\rightarrow$ Ewing sarcoma.
$\bullet$ Lytic lesion with rings-and-arcs / popcorn calcification $\rightarrow$ chondrosarcoma.
$\bullet$ Eccentric expansile soap-bubble lytic lesion at the epiphysis of a fused bone $\rightarrow$ giant cell tumour (osteoclastoma).
Conclusion: A sunburst lesion = osteosarcoma (option A).
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