36: Bone and Soft Tissue Tumours

Question 1

describe sarcoma and their spread

Answer 1

• malignant tumours arising from connective tissues
• spread along fascial planes
• haematogenous spread to lungs
• rarely spread to regional lymph nodes (rhabdomyosarcomas, epitheloid sarcomas & synovial sarcomas)

Question 2

a bone tumour in a patient > 50 is likely to be?

Answer 2

metastatic

Question 3

give examples of benign and malignant bone-forming tumours

Answer 3

• benign: osteoid osteoma, osteoblastoma
• malignant: osteosarcoma

Question 4

give examples of benign and malignant cartilage-forming tumours

Answer 4

• benign: endochondroma, osteochondroma
• malignant: chondrosarcoma

Question 5

give examples of benign and malignant fibrous tissue tumours

Answer 5

• benign: fibroma
• malignant: fibrosarcoma, malignant fibrous histiocytoma (MFH)

Question 6

give examples of benign and malignant vascular tissue tumours

Answer 6

• benign: hemangioma, aneurysmal bone cyst
• malignant: angiosarcoma

Question 7

give examples of benign and malignant adipose tissue tumours

Answer 7

• benign: lipoma
• malignant: liposarcoma

Question 8

give examples of malignant marrow tissue tumours

Answer 8

• Ewing’s sarcoma
• lymphoma
• myeloma

Question 9

what is the most common primary malignant bone tumour in a younger patient?

Answer 9

osteosarcoma

Question 10

what is the most common primary malignant ‘bone’ tumour in an older patient?

Answer 10

myeloma

Question 11

what is the most useful imaging modality for suspected bone lesions?

Answer 11

plain x-rays

Question 12

inactive bone lesion x-ray features

Answer 12

• clear margins
• surrounding rim of reactive bone
• cortical expansion can occur with aggressive benign lesions

Question 13

aggressive bone lesion x-ray features

Answer 13

• less well-defined zone of transition between lesion and normal bone (permeative growth)
• cortical destruction = malignancy
• periosteal reactive new bone growth occurs when the lesion destroys the cortex
• Codman’s triangle, onion-skinning or sunburst pattern

Question 14

what is the complete work up of investigations prior to bone biopsy?
bone lesion investigations

Answer 14

• Bloods
• x-ray of affected limb and chest, most useful for bone lesions
• MRI of lesion
• bone scan
• CT CAP

Question 15

what are the cardinal clinical features of malignant primary bone tumours?

Answer 15

• increasing pain
• unexplained pain
• deep-seated aching
• night pain
• difficult weight-bearing
• deep swelling

Question 16

osteosarcoma clinical features

Answer 16

• pain: increasing, worse at night, deep borin ache
• loss of function: limp, reduced ROM, stiff back esp. child
• swelling: generally diffuse, warmth over swelling + venous congestion = active!
• pathological fracture
• joint effusion
• deformity
• neurovascular effects
• systemic effects of neoplasia

Question 17

osteosarcoma investigation of choice

Answer 17

MRI scan
- very sensitive
- very good for showing extent of tumour, joint involvement, skip metastases, epiphyseal extension
- determines resection margins

Question 18

what are suspicious signs that a soft tissue tumour could be malignant?

Answer 18

• deep (i.e. deep to deep fascia) tumours of any size
• subcutaenous tumours > 5cm
• rapid growth, hard, craggy, non-tender

Question 19

BEWARE swelling which is..

Answer 19

• rapidly growing
• hard, fixed, craggy surface, indistinct margins
• non-tender to palpation, but assoc. with deep ache, esp. worse at night
• may be painless
• recurred after previous excision

Question 20

what is more common, a primary or a secondary bone tumour?

Answer 20

• secondary is 25x more common

Question 21

list the 7 most common primary cancers which metastasise to bone

Answer 21

1. breast, most common
2. lung
3. prostate
4. kidney
5. thyroid
6. GI tract
7. melanoma

Question 22

how can a pathological bone fracture be prevented?

Answer 22

• early chemotherapy/DXT
• prophylactic internal fixation
• +/- use of bone cement

Question 23

what is the most common soft-tissue tumour

Answer 23

lipoma