MALIGNANT BONE TUMOURS Flashcards
Malignant Bone Tumours
Malignant primary bone tumours are very rare when considered alongside other forms of primary malignancy.
M- malignant primary bone tumour aggressive and destructive signs on x‐ray (4)
cortical destruction
a periosteal reaction (raised periosteum producing bone)
new bone formation (sclerosis as well as lysis from destruction)
extension into the surrounding soft tissue envelope.
M- most common form of primary bone tumour
osteosarcoma
M- What is an osteosarcoma
malignant tumour of the bone
osteosarcoma age group
Most cases are seen in younger age groups (adolescence and early adulthood)
common sites of osteosarcoma and mets (5)
Most common site is the knee.
Second most common sites include the proximal femur, proximal humerus and pelvis.
Metastatic spread is usually haematogenous but can be lymphatic
Metastatic spread is usually haematogenous but can be lymphatic.
10% of patients have pulmonary metastases at diagnosis.
osteosarcoma treatment
Whilst they are not radiosensitive, adjuvant chemotherapy can prolong survival.
M- What is a chondrosarcoma
cartilage producing primary bone tumour and is less common and less aggressive than osteosarcoma.
chondrosarcoma age group
V
chondrosarcoma sites and mets (2)
can be very large and are slow to metastasize
tend to be found in the pelvis or proximal femur.
chondrosarcoma treatment (2)
prognosis is dependant on the histological grade with the majority being low grade.
not radiosensitive and unresponsive to adjuvant chemotherapy thus far.
M- what is a fibrosarcoma and malignant fibrous histiocytoma (3)
fibrous malignant primary bone tumours which tend to occur in abnormal bone
(bone infarct, fibrous dysplasia, post irradiation, Paget’s disease).
Fibrosarcona tends to affect adolescents or young adults.
M- what is ewing’s sarcoma (6)
a malignant tumour of primative cells in the marrow
2nd most prevalent primary bone tumour and has the poorest prognosis.
ewings sarcoma age group
most cases occur between the ages of 10 and 20
ewings sarcoma symptoms (2)
associated with fever, raised inflammatory markers and a warm swelling
may be misdiagnosed as osteomyelitis.
ewings sarcoma treatment
tends to be radio‐ and chemo‐sensitive.
diagnosing a primary malignant bone tumour (4)
staging investigations usually include bone scan and CT chest.
MRI and CT are useful to determine the local extent of the tumour and the involvement of muscle, nerves and vessels.
biopsy is required for histological diagnosis and grading prior to definitive surgery.
bone tumour is removed with a wide margin of 3‐4cm of bone and a cuff of normal muscle all around.
M- treatment of primary bone tumours (6)
surgery to remove the tumour and surrounding tissue to reduce the risk of recurrence.
amputations used to be more commonly employed to minimize recurrence risk but with improved adjuvant therapy, limb salvage surgery has equivalent success rates and better functional outcome, if appropriate.
M- Metastatic bone tumours (5)
(in order of frequency):
Breast carcinoma
Prostate carcinoma
Lung carcinoma
Renal cell carcinoma
Thyroid adenocarcinoma
M-Renal cell carcinoma (3)
gives rise to potentially large and very vascular lytic “blow out” bony metastases which can bleed tremendously with biopsy or surgery.
surgery can potentially be curative.
Mean survival with multiple bone metastases is 12‐18 months.
M- Prostate cancer (3)
Prostate cancer commonly metastasizes to bone and produces sclerotic metastases. Because of the osteoblastic activity pathologic fractures are more likely to heal.
Radiotherapy and hormone manipulation can reduce the fracture risk of a bone metastasis.
Survival with prostatic bony metastases is around 45% at one year.
M-Breast cancer
Breast cancer bony metastases can be blastic (sclerotic) or lytic.
Mean survival with bony metastases is around 24‐26 months.
M- Lung cancer
Lung cancer usually gives rise to lytic bony metastases and once bone metastases are present, mean survival is around 6 months.
M- Bones most frequently involved with metastases (5)
vertebra, pelvis, ribs, skull, humerus and long bones of the lower limb.
The pain misdiagnosed as a muscle strain however any pain with “red flags” should be investigated at least with an xray initially.
present with pathological fracture.
lesion is found on xray, a primary bone tumour must be excluded (by bone scan and occasionally MRI).
Bone scan will also demonstrate the extent of bone metastases.
