Other bone tumours can present in a similar manner (Ewings Sarcoma, Chondrosarcoma)
Joint pain and swelling is common in adolescents and a high degree of suspicion is required to ensure that disaster is averted. For example:
Knee pain in an adolescent can be caused by many conditions including:
- Patellofemoral malalignment
- Slipped capital femoral epiphysis
- Ligamentous injuries
- Osood-Schlatter’s disease
- Osteochondritis dissecans
- Juvenile rheumatoid arthritis
The following guidelines can help to differentiate these conditions from osteosarcoma:
1. Pain due to an osteosarcoma is often located away from the joint line and over the metaphysis
2. The pain often has a different nature – night pain which is not related to activity.
3. Persists after physiotherapy or other treatment
4. Associated systemic symptoms of malaise.
5. A soft tissue mass (firm and palpable) should be distinguished from an effusion (fluctuant and anterior).
6. Lack of physical findings in support of the other diagnoses (eg patellofemoral syndrome patients should have evidence of malalignment before their pain is ascribed to that)
However none of these is definitive, and vigilance and re-assessment is necessary.
The key to making the diagnosis is to perform an xray early if the symptoms and signs are at all suspicious.
Persisting Pain and a Soft Tissue Mass are the two most important clinical indicators of Osteosarcoma.
The radiological appearances are described later. Usually the diagnosis is clear, but the differential diagnosis can include osteomyelitis and other bone tumours.
Biopsy by a bone tumour specialist is always required to obtain histological confirmation before proceeding with surgery.