Bone Tumours

Question 1

which is the most common primary bone tumour

Answer 1

myeloma

Question 2

Name some common sites for cancer to metastasise from to the bone

Answer 2

bronchus, breast, prostate, kidney, thyroid (follicular), renal, bowel

Question 3

give some effects of metastases in bone

Answer 3

Bone pain, bone destruction, pathological fractures in long bones, spinal metastases can cause wedge fracture in the vertebral column which can progress to vertebral collapse, spinal cord compression etc.
Hypercalcaemia

Question 4

name the two types of metastases you see in bones

Answer 4

lytic and sclerotic

Question 5

name two cancers that give sclerotic bone metastases

Answer 5

prostate cancer and breast cancer

Question 6

how will a sclerotic metastasis appear on x-ray

Answer 6

brighter as it is more dense due to the woven bone that has been deposited

Question 7

what type of bone do sclerotic metastases induce the production of and which cells lay it down

Answer 7

woven bone

Laid down by osteoblasts

Question 8

how does a lytic metastasis lead to bone destruction

Answer 8

tumour releases cytokines which activate osteoclasts which then destroy the bone

Question 9

which cancers typically cause a solitary bone metastasis

Answer 9

renal and thyroid carcinoma

Question 10

Name some of the clinical effects of myeloma

Answer 10

bone lesions - punched out lytic foci, generalised osteopaenia, tendency to fracture.
Marrow replacement - anaemia, infections (WBCs), thrombocytopaenia - bleeding risk.
Immunoglobulin excess - can have major effect on the kidney and lead to kidney failure.

Question 11

name some lab/imaging findings in myeloma

Answer 11

pepper-pot skull
Huge proliferations of either kappa or lambda only - mono-proliferation is occurring.
ESR>100. Serum electrophoresis will show a monoclonal band. Urine - immunoglobulin light changes: Bence Jones protein.

Question 12

how is osteoid osteoma treated

Answer 12

radio-frequency ablation

Question 13

what causes osteoid osteoma

Answer 13

nidue of osteoblasts located in the cortex of the bone. It is a benign proliferation and is self-limiting

Question 14

what are the symptoms of osteoid osteoma and how are they relieved

Answer 14

pain, which is worse at night. Scoliosis of the spine is often present.
Pain is completely relieved by aspirin.

Question 15

what is an osteosarcoma?

Where does it normally affect ?

Answer 15

Primary bone tumour.
Malignant tumour whose cells form osteoid or bone.
Metaphysis of long bones, with half affecting the area around the knee.

Question 16

what is the peak age for osteosarcoma

Answer 16

10-25 but can be seen in later years in those who have received radiotherapy earlier in life for another reason.

Question 17

describe the natural history of osteosarcoma

Answer 17

highly maligant, destroys local cortex and metastasises early, often to the lugs.

Question 18

how is osteosarcoma treated?

Answer 18

8 weeks of chemotherapy followed by excision.

Question 19

what is Codman’s sign (or triangle)

Answer 19

where there is a triangle appearance in the cortex of the bone as the tumour has spread out very quickly through the cortex and has begun to form a new cortex

Question 20

what is Paget’s disease

Answer 20

disease of excessive bone remodelling. Caused by osteoclasts - osteoblasts are then activated in response to the osteoclasts and lay down weak, disorganised bone.
Areas of bone becoming abnormally large and deformed with increased vascularity

Question 21

what symptoms would someone with Paget’s disease have and what are the effects of the disease

Answer 21

• Bone pain
• Deformity – bowing of long bones
• Pathological fracture, especially in the hip. Osteoarthritis can develop.
• Osteoarthritis
• Deafness – thickened skull can compress the 8th cranial nerve
• Spinal cord compression – due to the effect on the vertebral body.
• High cardiac output – cardiac failure. Bone formed is very vascular so puts high demands on blood output from the heart.
• Paget’s sarcoma

Question 22

what is an endochondroma ?

Answer 22

lobulated mass of acrtilage within the medulla. Benign. Occurs in hands, feet, long bones.

Question 23

what is an Osteocartilaginous exostosis

Answer 23

benign outgrowth of cartilage with endo-chondral ossification.
Probably occurs from the growth plate and are very common, especially in adolescence. Only danger is if they grow very large as a chondrosacroma can arise within it

Question 24

describe a chondrosarcoma

Answer 24

Can be a primary lesion or can be secondary - conversion of a benign cartilagenous tumour such as a osteochondroma or chondroma.
Can be low or high grade. Most common areas are in the pelvis and around the hip.
Can be central, within the medullary canal or peripheral: on the bone surface.
Managed using surgery