Question

What is the most likely diagnosis for the lesion shown here?

• A. Sunburst appearance
• B. Onion-skin appearance
• C. Codman’s triangle
• D. Ground glass appearance

Hint:

The sunburst pattern is often seen in aggressive bone tumors like osteosarcoma and is a key diagnostic feature on radiographs.

Answer 1

The Correct Option is A

Step 1: Recognise the radiological pattern.
The image shows fine, radiating spicules of new bone streaming outward from the cortex, like rays from the sun. This perpendicular spiculated periosteal reaction is described as a sunburst (sunray) appearance and is a classic aggressive bone-lesion sign, most associated with osteosarcoma.

Step 2: Why this pattern arises.
When a fast-growing tumour breaks through the cortex, it lays down bone along the stretched, lifted periosteal vessels, producing the radiating spicules seen here. The aggressive, perpendicular pattern distinguishes it from slower benign reactions.

Step 3: Separate it from the other named reactions.
• Onion-skin appearance - concentric, multilayered periosteal lamellae (typical of Ewing sarcoma), not radiating rays, so it does not match.
• Codman's triangle - a triangular cuff of reactive bone where the elevated periosteum meets cortex; it is a localized angular lift, not the diffuse radiating spicules shown.
• Ground-glass appearance - a hazy, homogenous matrix (e.g., fibrous dysplasia), the opposite of the sharp radiating lines here.

Step 4: Conclude.
The radiating, sun-ray spicules identify the lesion as a sunburst appearance.

Final answer: Option 1 - Sunburst appearance.