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Benign bone tumours and tumour-like lesions
Most bone lesions in children and young adults are benign and can be recognised by site, appearance and symptoms; treatment ranges from observation alone to curettage and grafting, and only a few carry a risk of malignant change.
Why it matters in the exam
Questions present a typical finding and ask you to identify the lesion and its treatment. Osteochondroma is the most common benign tumour: a bony projection with a cartilage cap in the metaphysis that grows away from the joint and stops growing at the end of growth; growth or pain in adult life, or a cartilage cap thicker than 2 cm, suggests change to chondrosarcoma, especially in hereditary multiple exostoses. Osteoid osteoma appears in a young patient with night pain that settles quickly with non-steroidal anti-inflammatory drugs; radiographs show cortical sclerosis around a small nidus of less than 1.5 cm, and CT is the best test. The preferred treatment today is CT-guided radiofrequency ablation. Enchondroma is common in the bones of the hand, with popcorn-like calcification; multiple enchondromas (Ollier and Maffucci syndromes) raise the risk of malignancy. Giant cell tumour appears at age 20–40 in the epiphysis, reaching just under the joint cartilage, mainly around the knee; it is locally aggressive and tends to recur after curettage. A simple bone cyst appears in children in the proximal humerus and is often found through a fracture with a fallen fragment sign, while an aneurysmal bone cyst shows fluid levels within the lesion on MRI. Non-ossifying fibroma is a common incidental finding that disappears on its own and needs no biopsy. The key exam principle is to recognise when observation is enough and when referral is needed.
Key points
- Osteochondroma is the most common benign tumour; growth in adult life suggests malignant change.
- Osteoid osteoma: night pain relieved by anti-inflammatories, treated by ablation.
- Giant cell tumour: epiphysis after physeal closure, age 20–40.
- Simple bone cyst in the proximal humerus of a child, sometimes with fracture.
- An inactive, typical lesion is managed by observation only.
Summary table
| Lesion | Age and site | Identifying feature | Treatment |
|---|---|---|---|
| Osteochondroma | Children and adolescents; metaphysis around the knee | Bony projection continuous with the medulla, cartilage cap | Observation; excision if it presses on structures or hurts |
| Osteoid osteoma | Age 10–30; cortex of femur and tibia | Night pain relieved by anti-inflammatories; nidus smaller than 1.5 cm | CT-guided radiofrequency ablation |
| Enchondroma | Young adults; bones of the hand | Popcorn-like calcification | Observation; curettage if painful or after fracture |
| Giant cell tumour | Age 20–40; epiphysis around the knee | Eccentric lytic lesion reaching the joint cartilage | Extended curettage with adjuvant and filling; sometimes denosumab |
| Simple bone cyst | Children; proximal humerus | Fallen fragment sign | Observation or injection; treat the fracture |
| Non-ossifying fibroma | Children; metaphysis of a long bone | Eccentric lesion with a scalloped sclerotic rim | Observation only, no biopsy |
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Sources
- Campbell's Operative Orthopaedics, 14th ed. (2021) — Benign Bone Tumors and Nonneoplastic Conditions Simulating Bone Tumors
- AAOS Comprehensive Orthopaedic Review, 3rd ed. (2019) — Benign Bone Tumors and Tumor-like Lesions
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.