Imaging recommendation · Musculoskeletal

Bony protuberance with cortical continuity, suspected osteochondroma

Q: What's the alternative imaging for bony protuberance with cortical continuity, suspected osteochondroma when cartilage cap > 1.5 cm, growth in adult, pain?

MRI — MRI with cartilage cap measurement (iv contrast).

Recommended: X-ray (often sufficient) + MRI to measure cartilage cap is the preferred imaging study for bony protuberance with cortical continuity, suspected osteochondroma. Most common benign bone tumor.

Recommended study

X-ray (often sufficient) + MRI to measure cartilage cap

XR No contrast Preferred Musculoskeletal Outpatient Reviewed 2026-05

Most common benign bone tumor. Cortical and medullary continuity is pathognomonic.

If the default doesn't apply

Cartilage cap > 1.5 cm, growth in adult, pain

MRI MRI with cartilage cap measurement IV contrast

Watch-outs

Chondrosarcoma transformation

Cartilage cap > 1.5-2 cm in adult or pain in stable lesion suggests malignant transformation.

Hereditary multiple exostoses (HME)

EXT1/EXT2 mutations; multiple lesions; lifetime malignancy risk ~5%; surveillance imaging.

Pearls

Sessile or pedunculated; pedunculated grow away from joint.
Cartilage cap on MRI: T2 bright, calcifying with age (thicker cap in growing child is normal).
Complications: fracture, vascular impingement, neurologic compression, bursa formation, malignancy.