MALIGNANT BONE TUMOURS

Question 1

Malignant Bone Tumours

Answer 1

Malignant primary bone tumours are very rare when considered alongside other forms of primary malignancy.

Question 2

M- malignant primary bone tumour aggressive and destructive signs on x‐ray (4)

Answer 2

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.

Question 3

M- most common form of primary bone tumour

Answer 3

osteosarcoma

Question 4

M- What is an osteosarcoma

Answer 4

malignant tumour of the bone

Question 5

osteosarcoma age group

Answer 5

Most cases are seen in younger age groups (adolescence and early adulthood)

Question 6

common sites of osteosarcoma and mets (5)

Answer 6

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.

Question 7

osteosarcoma treatment

Answer 7

Whilst they are not radiosensitive, adjuvant chemotherapy can prolong survival.

Question 8

M- What is a chondrosarcoma

Answer 8

cartilage producing primary bone tumour and is less common and less aggressive than osteosarcoma.

Question 9

chondrosarcoma age group

Answer 9

V

Question 10

chondrosarcoma sites and mets (2)

Answer 10

can be very large and are slow to metastasize

tend to be found in the pelvis or proximal femur.

Question 11

chondrosarcoma treatment (2)

Answer 11

prognosis is dependant on the histological grade with the majority being low grade.

not radiosensitive and unresponsive to adjuvant chemotherapy thus far.

Question 12

M- what is a fibrosarcoma and malignant fibrous histiocytoma (3)

Answer 12

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.

Question 13

M- what is ewing’s sarcoma (6)

Answer 13

a malignant tumour of primative cells in the marrow

2nd most prevalent primary bone tumour and has the poorest prognosis.

Question 14

ewings sarcoma age group

Answer 14

most cases occur between the ages of 10 and 20

Question 15

ewings sarcoma symptoms (2)

Answer 15

associated with fever, raised inflammatory markers and a warm swelling

may be misdiagnosed as osteomyelitis.

Question 16

ewings sarcoma treatment

Answer 16

tends to be radio‐ and chemo‐sensitive.

Question 17

diagnosing a primary malignant bone tumour (4)

Answer 17

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.

Question 18

M- treatment of primary bone tumours (6)

Answer 18

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.

Question 19

M- Metastatic bone tumours (5)

Answer 19

(in order of frequency):

Breast carcinoma
Prostate carcinoma
Lung carcinoma
Renal cell carcinoma
Thyroid adenocarcinoma

Question 20

M-Renal cell carcinoma (3)

Answer 20

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.

Question 21

M- Prostate cancer (3)

Answer 21

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.

Question 22

M-Breast cancer

Answer 22

Breast cancer bony metastases can be blastic (sclerotic) or lytic.

Mean survival with bony metastases is around 24‐26 months.

Question 23

M- Lung cancer

Answer 23

Lung cancer usually gives rise to lytic bony metastases and once bone metastases are present, mean survival is around 6 months.

Question 24

M- Bones most frequently involved with metastases (5)

Answer 24

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.