Osteosarcoma is the most common primary malignant tumour of bone, excluding plasma cell myeloma. It is an aggressive tumour that most commonly causes patients to die from pulmonary metastatic disease.

The top three affected areas are the distal femur, the proximal tibia, and the proximal humerus, but virtually any bone can be affected.  It is commonest in teenagers, with a bimodal distribution affecting a smaller number of elderly patients.  A small number of cases of Paget’s disease of the bone may undergo osteosarcomatous change.

In the United States, the incidence of osteosarcoma is 400 cases per year (4.8 per million population).  If this is adjusted for the population of Brunei this equates to 1.9 cases per year in Brunei.

The mainstay of therapy is surgical removal of the malignant lesion. Most often, limb-sparing (limb-preserving) procedures can be used to treat patients with this disease and, thus, preserve function. Chemotherapy is also required to treat micro-metastatic disease.


Radiographic Features

Plain film is almost always the initial imaging modality.

Features suggestive of osteosarcoma include;

  1. Ill defined sclerotic bone lesion, usually in the metaphyseal region
  2. Bony destruction
  3. Periosteal reaction – classically ‘sunburst’ in nature with evidence of Codman’s triangle.
  4. Variable soft tissue component


Once the diagnosis is suspected, magnetic resonance imaging (MRI) is essential to determine the distribution of the tumour within the bone and the extent of any associated soft tissue mass.  The whole bone should be imaged to exclude synchronous lesions. Computed tomography (CT) is used in staging the tumour to assess for pulmonary metastases.  Osteosarcoma is one of the tumours associated with ‘cannon ball’ metastases, along with renal cell carcinoma, testicular cancer and choriocarcinoma. 


Images prepared by Dr Ian Bickle, Consultant Radiologist, RIPAS Hospital, Brunei Darussalam.

All images are copyrighted and property of RIPAS Hospital.