1. Bone Malignancies

2. Primary bone tumours Primary bone tumours are rare
Secondaries tumours are more common especially in the elderly

4. Clinical features
Most present with pain, swelling and localised tenderness
Rapid growth and erythema are suggestive of malignancy
May cause pathological fractures
Diagnosis confirmed by:
Plain x-ray
CT scan
Bone scan
Carefully planned biopsy

5. Osteoid osteoma Benign bone tumour
Usually less than 1 cm in diameter and surround by dense osteoid
Occurs in young adults
Tibia and femur are the commonest site
Pain (relieved by aspirin) is presenting complaint
Xray has characteristic appearance of a radiolucency surrounded by dense bone
Local excision is curative

6. Osteochondroma Commonest bone tumour Lesions can be single or multiple
Appears in adolescence as cartilaginous overgrowth at epiphyseal plate
Grows with underlying bone
Metaphyses of long bones are the commonest sites
Presents as painless lump or occasionally joint pain
Excision should be considered if causing significant symptoms

7. Chondroma Benign tumour of cartilage
Lesions may be single or multiple (Ollier's disease)
Appears in tubular bones of hands and feet
Xray shows well defined osteopenic area in the medulla
Lesion should excised and bone grafted

8. Osteoclastoma
Equal proportions are benign, locally invasive and metastatic
Found in sub-articular cancellous region of long bones
Only occurs after closure of epiphyses
Patients are usually between 20 and 40 years
Xray shows an asymmetric rarefied area at the end of a long bone
Cortex is thinned or even perforated
Treatment by local excision and grafting often leads to recurrence
Wide excision and joint replacement is the treatment of choice
Amputation if malignant or recurrent tumour

9. Osteosarcoma Occurs in the metaphyses of long bones
Commonest sites are around the knee or proximal humerus
Destroys bone and spreads into the surrounding tissue
Rapidly metastasizes to the lung
Usually occurs between 10 and 20 years
In later life is seen associated with Paget's disease
X-ray shows combination of bone destruction and formation

10. Osteosarcoma Periosteum may be lifted (Codman's triangle)
Soft tissue calcification produces a 'sunburst' appearance
Treatment involves amputation and chemotherapy
Amputations are often limited with prosthetic replacement
50% five years survival
Worst prognosis seen with proximal and axial skeletal lesions

13. Secondary bone tumours

14. 2ry bone tumours
30% of patients with malignant disease will develop bone metastases
10% of these patients will develop a pathological fracture
Tumours spread to bone by:
Direct invasion
Haematogenous spread
Lymphatic spread
Spread via paravertebral venous plexus
Commonest sites lumbar vertebrae, pelvis and ribs

15. 1ry tumours which spread to the bone
Breast  (35%)
Prostate  (30%)
Bronchus (10%)
Kidney  (5%)
Thyroid  (2%)
Others (18%)

16. Clinical features Pain or localised bone lump Pathological fracture
Hypercalcaemia
Cord compression

17. Radiology Plain x-rays can be normal
If abnormal will show either an osteolytic or sclerotic lesion

18. Radiology Bone scan has higher sensitivity than x-rays
May identify other asymptomatic lesions

19. DD Calcified enchondroma Hyperparathyroidism
Chronic sclerosing osteomyelitis
Bone infarct
Myeloma deposit

20. Tx The aims of treatment are to relieve pain and preserve mobility
If pathological fracture consider internal fixation for early mobilisation and pain relief
Consider radiotherapy for back pain
Spinal decompression may be needed for cord compression
Prophylactic internal fixation may be required if:
Greater than 50% erosion of a long bone cortex
A metastasis of more than 2.5 cm in diameter
Metastasis in high risk area (e.g. subtrochanteric femur)
Metastasis with persistent pain