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Approach to a bone lesion and bone tumours
Three questions guide the differential diagnosis of a bone lesion: the patient's age, the lesion's location in the bone and how aggressive it looks on radiographs; biopsy comes only after full imaging, at the centre that will perform the definitive surgery.
Why it matters in the exam
Questions in this area show a radiograph of a lesion and an age and ask for the likely diagnosis or the next step. Age is the most important clue: under age 5 think of metastatic neuroblastoma or Langerhans cell histiocytosis; at age 10–25 think of osteosarcoma and Ewing sarcoma; above age 40 a destructive lesion is usually a metastasis or multiple myeloma, and chondrosarcoma appears mainly in middle age. Location adds information: in the epiphysis — chondroblastoma in children and giant cell tumour (GCT) after physeal closure; in the metaphysis — osteosarcoma, osteochondroma and non-ossifying fibroma; in the diaphysis — Ewing sarcoma and histiocytosis. Signs of aggressiveness include a wide zone of transition, permeative destruction, a sunburst or onion-skin periosteal reaction or a Codman triangle, and a soft tissue mass. A particularly common question is the next step in a patient older than 40 with a single destructive lesion: first a work-up for metastasis and myeloma, and only then biopsy. A classic error is a biopsy at a non-specialist centre through an unsuitable incision, which can contaminate tissue and prevent limb-sparing surgery. The mode of presentation also matters: a lesion found incidentally that does not hurt is usually benign. A painful lesion, one that grows on repeat radiographs or one with a pathological fracture needs faster assessment, even if it does not look especially aggressive.
Key points
- Three questions: age, location and aggressiveness.
- Under 5 — neuroblastoma; 10–25 — osteosarcoma and Ewing; above 40 — metastases and myeloma.
- Epiphysis — chondroblastoma and giant cell tumour; diaphysis — Ewing sarcoma.
- Aggressive signs: wide zone of transition, periosteal reaction and a soft tissue mass.
- Biopsy comes last, at the centre that will operate.
Summary table
| Feature | Benign or inactive lesion | Malignant or aggressive lesion |
|---|---|---|
| Zone of transition | Narrow and well defined, sometimes with a sclerotic rim | Wide, permeative or moth-eaten destruction |
| Periosteal reaction | Smooth and continuous, or none | Sunburst, onion skin or Codman triangle |
| Cortex and soft tissue | Cortex intact or only thinned | Cortical destruction and a soft tissue mass |
| Symptoms | Incidental finding, no or mild pain | Persistent pain, night pain, swelling and pathological fracture |
| Work-up | Radiograph and observation or focused MRI | MRI of the whole bone, chest CT, bone scan or PET, then biopsy at a specialist centre |
In the full version for subscribers
- A simple algorithm
- Memory aid
- Exam traps
- 5 review cards
- Enough for IMLE
The full version is open to subscribers of: Orthopedic surgery, Medical licensing exam (IMLE), Oncology.
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Sources
- Campbell's Operative Orthopaedics, 14th ed. (2021) — General Principles of Tumors
- ESMO-EURACAN-GENTURIS Clinical Practice Guidelines, 2021 — Bone Sarcomas
- AAOS Comprehensive Orthopaedic Review, 3rd ed. (2019) — Orthopaedic Oncology: Evaluation and Staging
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.