Malignant Bone Tumours Flashcards
What are the risk factor for malignant primary bone tumours?
- Previous radiotherapy
- Predisposing conditions: Paget’s, fibrous dysplasia, multiple enchondromas
- Genetic causes: Li Fraumeni syndrome (p53), familial retinoblastoma (RBI)
What is the clinical presentation of malignant primary bone tumours?
- Presentation is often late in the disease
- Higher index of suspicion in younger patients (10-30 years)
- Persistent, increasing pain
- Usually not associated with movement
- Well localised
- Worse at night
- Not uncommonly misdiagnosed for muscular pains - any unexplained persistent skeletal pain/red flags should be further investigated
- Pathological fracture
- Swelling and erythema over joint (especially in Ewing’s sarcoma)
- Palpable mass
What is multiple myeloma?
- Malignant disease of the plasma cells of the bone marrow
- Commonest primary tumour of bone
What is the clinical presentation of multiple myeloma?
- Generally affects elderly patients
- 4 main features are hypercalcaemia, anaemia, renal impairment and bone pain
What is osteosarcoma?
- Malignant tumour which produces bone
- Most common primary sarcoma of bone
- Metastatic spread is usually haematogenous but can be lymphatic
What is the clinical presentation of osteosarcoma?
- Most cases seen in adolescence and early adulthood
- 2nd peak in the elderly associated with Paget’s
- 60% involve the bones around the knee (distal femur/proximal tibia), other sites include proximal femur, proximal humerus and pelvis
- 10-20% of patients have pulmonary metastases at diagnosis - impacts survival
What is chondrosarcoma?
- Cartilage producing primary bone tumour - malignancy of chondrocytes
- Less common and less aggressive than osteosarcoma (generally - can be aggressive)
- Majority arise de novo, few arise from benign lesions (enchondroma, osteochondroma)
- Prognosis dependent on histological grade - majority are low grade
- Can be very large and are slow to metastasize
What is the clinical presentation of chondrosarcoma?
- Tends to be found in the older age group - mean age 45
- Tend to be found in the pelvis or proximal femur
What is Fibrosarcoma?
- Fibrous malignant primary bone tumours which tend to occur in abnormal bone e.g. bone infarct, post radiation
- Fibrosarcoma tends to affect adolescents/YAs
What is Ewing’s sarcoma?
- Primary bone tumour of the endothelial cells of the bone marrow
- 2nd commonest malignant bone tumour in children
- Characterised by loss of bone (lysis)
What is the clinical presentation of Ewings sarcoma?
- Affects young people 5-25 years of age, most common age 10-20
- Hot, swollen, tender joint or limb with raised inflammatory markers - can mimic infection
- Usually found in diaphysis of long bones - distal femur, proximal tibia
What are the investigations for malignant primary bone tumours?
- X-ray
- Biopsy required for histological diagnosis and grading before surgery
- Staging - bone scan, CT, MRI
What would an x-ray show in malignant primary bone tumours?
- aggressive and destructive signs including cortical destruction, a periosteal reaction, new bone formation (sclerosis and lysis), reactive cortical thickening (chondrosarcoma) and extension into the surrounding soft tissue envelope
- AP and lateral including joint above and below
- Bony lesions may not show up on x-rays until more than 50% of the cortical bone is lost - if x-ray normal but clinical suspicion is high perform further imaging
What is the management for malignant primary bone tumours?
- Surgery - removal of tumour and surrounding tissue, with joint reconstruction
- Adjuvant chemotherapy/radiotherapy used if appropriate
- Neo-adjuvant chemotherapy can improve survival
What margin is required for excision of a malignant primary bone tumour?
Typically margin of 3-4cm of bone and a cuff of normal muscle all around
Which primary malignant bone tumours are not sensitive to radiotherapy or chemotherapy?
Chondrosarcoma
Can adjuvant chemotherapy/radiotherapy help osteosarcoma?
Osteosarcomas are not radiosensitive but adjuvant chemotherapy can prolong survival
What are the most common cancers that metastasise to bone?
Breast cancer in females and prostate cancer in males.
Describe the metastases from breast cancer in bone.
Bony metastases can be blastic (sclerotic) or lytic
Describe the metastases from prostate cancer in bone.
Produces sclerotic metastases
Describe the metastases from lung cancer in bone.
Usually gives rise to lytic bony metastases
Describe the metastases from renal cell cancer in bone.
Usually gives rise to potentially large and very vascular lytic ‘blow out’ bony metastases which can bleed tremendously with biopsy or surgery
What other cancers can metastasise to bone?
Breast cancer
Prostate cancer
Lung cancer
Renal cell cancer
Thyroid cancer
What is the mean survival with breast cancer with bony metastases?
Mean survival with bony metastases is around 24‐26 months
What is the mean survival with prostate cancer with bony metastases?
Survival with prostatic bony metastases is around 45% at one year
What is the mean survival with lung cancer with bony metastases?
Once bone metastases are present, mean survival is around 6 months
What is the mean survival with renal cell cancer with bony metastases?
Mean survival with multiple bone metastases is 12‐18 months
What bones are frequently involved with metastases?
vertebra, pelvis, ribs, skull and femurs
What investigations should be done for metastatic bone tumours?
- X-ray
- Other imaging - bone scan, occasionally MRI
- If there are multiple metastases or the lesion is suspected to be metastatic, the primary tumour should be sought
- Blood tests - serum calcium (for hypercalcaemia), LFTs (to look for liver mets), plasma protein electrophoresis (for myeloma), full blood count and U&E
What findings will be present on x-ray for metastatic bone tumours?
- Can appear as lytic, sclerotic or mixed
- If a lesion is found on xray, a primary bone tumour must be excluded by further imaging
- Lesion not visible on x-ray until >50% of cortex destroyed - if clinical suspicion high carry out further imaging
