Bone Malignancies

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

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

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

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

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

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

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

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

Secondary bone tumours

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

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

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

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

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

DD Calcified enchondroma Hyperparathyroidism Chronic sclerosing osteomyelitis Bone infarct Myeloma deposit

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