Bone and Soft Tissue Tumours

Question 1

What is a sarcoma?

Answer 1

Malignant tumour of connective or non-epithelial tissue

bone, cartilage, fat, vascular or haematopoietic tissues

Question 2

Bone tumours can be…

Answer 2

Benign (normally)
Malignant (rare)
Secondary (common)
a bony tumour if Pt. >50 y/o likely to be metastatic

Question 3

How do sarcomas spread?

Answer 3

Along fascial planes (rarely)
Haematogenous (to lungs)
Lymphatic (regional, rarer, found in rhabdomyosarcomas, epithelioid, synovial sarcomas)

Question 4

Grades of sarcoma?

Answer 4

Low, medium, high

Often present as aggressive, high grade tumours

Question 5

Investigations for Sarcoma?

Answer 5

MRI better than x-ray (better dermarcation, shows soft tissue and bone involvement leading to better management)

Question 6

Types of bone-forming tumour

Answer 6

Benign: osteoid osteoma, osteoblastoma
Malignant: osteosarcoma

Question 7

Types of cartilage-forming tumour

Answer 7

Benign: endochondroma, osteochondroma
Malignant: chondrosarcoma

Question 8

How are chondrosarcomas treated?

Answer 8

Low grade can be curetted

Unresponsive to chemotherapy or radiotherapy

Question 9

Types of fibrous tissue tumour

Answer 9

Benign: fibroma Malignant: fibrosarcoma, malignant fibrous histiocytoma (MFH)

Question 10

Describe malignant fibrous histiocytoma (MFH) and who it normally presents in

Answer 10

Pleomorphic
High grade
Most common type of soft tissue sarcoma for extremities
Over 50s, more common in men

Question 11

Types of vascular tissue tumour

Answer 11

Benign: haemangioma, aneurysmal bone cyst
Malignant: angiosarcoma (aggressive)

Question 12

Types of adipose tissue tumour

Answer 12

Benign: lipoma
Malignant: liposarcoma

Question 13

Types of marrow tissue tumour

Answer 13

Malignant: Ewing’s sarcoma, lymphoma, myeloma

Question 14

Ewing’s sarcoma is common in…

Answer 14

Adolescents (14-18)

Question 15

Myeloma presentation

Answer 15

Bone problems
Multiple lytic lesions
Negative isotope bone scans (plasma cells are affected, osteocytes not affected)

Question 16

Describe Giant cell tumours

Answer 16

Usually benign (2% malignant)
Difficult to treat, unpredictable Uncommon
Characterized by the presence of multinucleated giant cells (osteoclast-like cells)
If malignant degeneration does occur, metastasises to the lungs.

Question 17

Tumour like lesions include…

Answer 17

Simple bone cysts Fibrous cortical defects

Question 18

Examination of tumours and lumps

Answer 18

General health 
Location
Shape
Consistency
Mobility/tethered (to muscle/bone/fat), 
Pain
Local temperature
Neurovascular deficit

Question 19

Using X-ray to investigate tumours, benign and malignant

Answer 19

Useful for bone lesions.
Benign tumours: clear margins, surrounded by reactive bone - maybe cortical invasion
Malignant: Poorly defined transition zone. Cortical destruction, new growth, ‘Onion skinning’: periosteum stretches up to give way to new bone

Question 20

When to use CT scanning for tumours

Answer 20

Staging (esp. if lung co-involvement)
Assessing ossification and calcification
Assess cortical integrity
Checking for lucent nidus in osteoid osteoma (central zone: atypical bone enclosed in well vascularized stroma, outer sclerosis)

Question 21

Isotope bone scans are used for…

Answer 21

Staging skeletal metastases
Ruling out myeloma (-ve Isotope scan)
Identifying multiple lesions of chondromas, early and malignant dysplasias
Increased uptake in benign tumours also

Question 22

When is MRI used for sarcomas?

Answer 22

Study of choice
Size, extent, anatomical relationships (To plan resection), shows disease limit in/out of bone
Specific for lipomas, haematoma, haemangioma, pigmented villonodular synovitis (nodular mass)
Not specific for weighing up benign vs. malignant (need histology etc.)

Question 23

What is pigmented villonodular synovitis?

Answer 23

Thickened, overgrown synovium

Leads to swelling, joint instability

Question 24

When is angiography used in tumours?

Answer 24

(rarely used)
Check involvement of vascular tree
Check integrity of vessels (MRI superior)
Check for embolisation of vascular tumours

Question 25

When is PET scanning used in tumours?

Answer 25

If amputation indicated

or Investigating chemotherapy response

Question 26

When to biopsy tumours?

Answer 26

After bloods, X-rays (limb and chest), MRI, bone scan, CT of chest, abdomen and pelvis (for staging purposes)
Use needle core or open biopsy
Diagnostic in 90%

Question 27

Managing sarcomas

Answer 27

Chemotherapy in children
Radiotherapy after operation Surgery: take clear margin of tissue with tumour (fascia too; removal vs preserving function)
Must know staging/extent before surgery
Plastics for reconstruction

Question 28

Identifying benign vs malignant

Answer 28

History (systemic symptoms)
Examination
Radiological (raised/reduced suspicion, check invasion or metastasis)
Biopsy (needle core or open)
Treatment varies (Need for reconstruction)

Question 29

Needle core vs open biopsy

Answer 29

Open: increased infection risk Needle core may accidentally sample necrotic tissue; need open to confirm

Question 30

Identifying lipoma

Answer 30

Looks like fat in all scans/sequences