MSK Tumours

Question 1

Difference between cortical and trabecullar bone

Answer 1

Compart (cortical) bone = hard outer shell of bone

Trabecular (spongey) bone = softer inner layer

Question 2

Name for immature and mature bone

Answer 2

Immature = woven

Mature = lamellar

Question 3

Common primary sites of metastatic bone disease

Answer 3

1. Lung, breast, prostate and colon adenocarcinoma
2. Thyroid adenocarcinoma
3. Renal cell carcinoma
4. Malignant melanoma

Question 4

Two types of bone metastases

Answer 4

Osteolytic metastases

• Most common
• Bone destruction by tumour cells
• Cytokines stimulate osteoclasts

Osteblastic metastases

• New bone formation
• Cytokines stimulate osteoblastic activity
• Prostate and breast carcinoma

Question 5

What is the most common primary malignancy of bone?

Answer 5

Plasma cell myeloma

Question 6

Pathology of plasma cell myeloma

Answer 6

Osteoclastic bone destruction

Multiple tumours

Clonal proliferation of plasma cells

Question 7

Clinical manifestations of plasma cell myeloma

Answer 7

• Bone pain
• Pathological fracture
• Hypercalcaemia from osteoclastic bone destruction
• Renal failure from paraprotein deposits in kidney

Question 8

Describe the prevalence of primary bone tumours compared to metastases and haematolymphoid malignancies

Answer 8

Primary bone tumours are rare

Question 9

How are primary bone tumours classfied?

Answer 9

By the type of matrix the tumour produces and if it’s benign or malignant

Question 10

Class the 6 types of primary bone tumours

Answer 10

Question 11

Describe osteosarcoma

Answer 11

Malignant mesenchymal neoplasm producing bone matrix

The most common primary tumour of the bone

Question 12

What radiological findings would you expect on osteosarcoma?

Answer 12

‘Codman’s triangle’

Lifting of the periosteum without new bone production, resulting in a ‘bulge’ on the side of the bone.

Question 13

Define osteoid osteoma

Answer 13

Benign bone forming tumour.

Question 14

Presentation of osteoid osteoma (symptoms)

Answer 14

Noctural pain highly responsive to NSAIDs

Occurs in long bones, within the cortex

Question 15

Describe enchondroma.

Where does it tend to occur?

Answer 15

Benign cartilaginous neoplasm.

Occurs primarily in small bones of hands and feet.

Question 16

What is the clinical presentation of enchondroma?

Answer 16

Asymptomatic, or pain and patholgoical fracture.

Question 17

How are enchondromas treated?

Answer 17

Scrape out the tumour - currettage.

Question 18

Describe osteochondroma. What type of bone does it occur in?

Answer 18

Osteochondromas are benign pedunculated tumour of bone with cartilage cap on top of the bony stalk.

Occurs on long bones

Question 19

How might osteochondroma present and what is the prognosis?

Answer 19

Mostly asymptomatic, may cause pain if the growth impinges a nerve.

Benign, can be excised if sympomatic.

Question 20

Describe fibrous dysplasia

Answer 20

Benign fibro-osseous tumour of bone.

Question 21

What is the name of the highly malignant small round blue cell tumour in bone?

Answer 21

Ewing sarcoma.