Bone and Soft Tissue Tumours

Question 1

Are primary or secondary malignant bone tumours more common?

Answer 1

Secondary (25x - bone metastases second most common after lung)

• Primary benign bone tumours are quite common but malignant bone tumours are almost always metastases

Question 2

What is a sarcoma? What are their metastatic properties?

Answer 2

Malignant tumour arising from connective tissue

• Often undergo haematogenous spread to the lungs, rarely to regional lymph nodes (bar a few)

Question 3

What is the most common primary malignant bone tumour? In which group does it occur most?

Answer 3

Osteosarcoma - tends to occur in younger patients

Myeloma is the most common primary malignant bone tumour in older patients

Question 4

How do bone tumours tend to present?

Answer 4

• Pain (progressive even at rest & at night - main symptom)
• Palpable mass (if later stages)
• Weight loss, fatigue, pyrexia
• Neuro-vascular deficit if the mass is pushing on a structure

Question 5

What are the characteristics of a swelling that may indicate the presence of a bone tumour?

Answer 5

• Rapid growth
• Hard, fixed position, craggy surface with indistinct margins
• Non tender to palpation but experience deep ache that’s worse at night

Question 6

What investigations are most useful for investigating bone and soft tissue tumours?

Answer 6

• MRI (best choice)
• XRay / CT / PET scan / Bloods
• Isotope bone scanning
• Biopsy

Question 7

How does a malignant bone tumour appear on X-Ray?

Answer 7

• Poorly defined margins
• Cortical destruction
• Extra whitening around the cortex itself (Codman’s triangle, onion skinning, sunburst pattern)

Question 8

How does isotope bone scanning work?

Answer 8

• Inject technetium and it’s taken up by osteoblasts and laid down instead of calcium
• Tumours will be most active bone tissue and so when scanning for the tumour there will be the most isotope at those points

Question 9

Which investigation allows for the exact type of tumour to be determined?

Answer 9

Biopsy & histology

Benign vs. Malignant & what type of tissue

Question 10

Where in the body do osteosarcoma’s tend to occur? Who tends to get them?

Answer 10

Distal femur and proximal tibia

Vast majority of cases in patients aged 10-13

Question 11

What are the clinical features of an osteosarcoma?

Answer 11

Pain

• Loss of function / swelling / fracture
• Joint effusion / deformity
• Systemic effects of neoplasia (weight loss / fever etc)

Question 12

Treatment of bone tumours?

Answer 12

• Chemo & radiotherapy

- Surgery

Question 13

What can be a major complication of a poorly performed bone biopsy?

Answer 13

Can spread the tumour along the bone biopsy line, makes it much harder to salvage limbs when performing excision surgery

Question 14

What are the most common places for bone metastases to occur?

Answer 14

Vertebrae > proximal femur > pelvis > ribs > sternum > skull

Question 15

7 most common primary cancers that metastasize to bone?

Answer 15

1. Lung
2. Breast
3. Prostate
4. Kidney
5. Thyroid
6. GI tract
7. Melanoma

Question 16

How does a pathological fracture impact the patients chances of survival?

Answer 16

Decreases

• How much decrease is dependent on the type and aggressiveness of the cancer itself

Question 17

What is Mirel’s Scoring System?

Answer 17

System used to decide whether prophylactic treatment to prevent pathological fracture is needed for secondary bone tumours

Question 18

What is the commonest soft tissue tumour?

Answer 18

Lipoma

Question 19

What is the best way to differentiate between a lipoma or a possible sarcoma?

Answer 19

Size - Lipoma’s mainly < 5cm

80% of deep sarcoma’s are > 5 cm

Also depth, if deep to fascia & not superficial more likely to be a sarcoma

Question 20

What are the characteristics of soft tissue tumours?

Answer 20

• Painless
• Mass deep to deep fascia

> 5cm

• Fixed and hard

Question 21

Investigations for suspected sarcoma?

Answer 21

MRI