What radiographic appearance is most characteristic of chondrosarcoma?

• A. Periosteal reaction without destructive features
• B. Joint space narrowing
• C. Cortical thickening and destruction
• D. Mixed lytic and sclerotic lesion

Answer: (C)

Chondrosarcoma tends to grow by cartilaginous production and invade bone, producing destructive changes in the cortex with possible cortical thickening from the bone’s reaction to the expanding tumor. On X-rays you often see endosteal scalloping and a cortical breach, and a soft-tissue mass may accompany the lesion. The presence of cortical destruction is the most characteristic feature indicating aggressive cartilaginous malignancy, which is why cortical thickening with destruction best fits chondrosarcoma.

The other patterns describe processes that are less specific for chondrosarcoma: a periosteal reaction without destruction is more typical of benign or less aggressive processes, joint space narrowing points to degenerative changes, and a mixed lytic-sclerotic pattern can be seen in several other conditions and is not as characteristic of chondrosarcoma as cortical destruction is.