The mnemonic
Sunburst, Onion, Soap bubble
What each word stands for
- SunburstOsteosarcoma, also Codman triangle
- OnionEwing sarcoma, layered periosteal reaction
- Soap bubbleGiant cell tumour at the epiphysis
Why it matters clinically
Allows a diagnosis from the radiograph before biopsy confirmation.
Where it stops being reliable
Signs are suggestive and overlap; histology is needed to confirm.
Teaching aid, still awaiting independent review. Confirm facts in a standard source.