Table 2.

List of clinical and imaging features used in the differential diagnosis between osteochondroma and secondary chondrosarcoma

Benign osteochondroma	Secondary chondrosarcoma
No pain (only for fracture, bursitis or compression of adjacent structures)	Can cause pain
No growth beyond skeletal maturity	Rapid growth, suspicious especially if after skeletal maturity
	Presence of calcifications (signal voids) beyond the stalk
No associated soft tissue mass	Presence of an associated soft tissue mass
Thin cartilagineous cap (≤1 cm)*	Thick cartilagineous cap (>1 cm [16])