Bone and Soft Tissue Tumours

Question 1

Define sarcoma

Answer 1

Malignant tumours arising from connective tissue

Question 2

What is the spread of sarcomas?

Answer 2

• Spread along fascial planes
• Haematogenous spread to lungs
• Rarely to regional lymph nodes (rhabdomyosarcomas, epithelioid sarcomas & synovial sarcomas)

Question 3

How common are benign and malignant tumours of the bone?

Answer 3

• benign tumours of skeleton common
• malignant tumours of skeleton RARE
• bony secondaries very common
• bone tumour in patient >50y likely to be metastatic

Question 4

What are the bone forming tumours?

Answer 4

–benign: osteoid osteoma, osteoblastoma

–malignant: osteosarcoma

Question 5

What are the cartilage forming tumours?

Answer 5

–benign: enchondroma, osteochondroma

–malignant: chondrosarcoma

Question 6

What are the fibrous tissue tumours?

Answer 6

–benign: fibroma

–malignant: fibrosarcoma, malignant fibrous histiocytoma (MFH)

Question 7

What are the vascular tissue tumours?

Answer 7

–benign: haemangioma, aneurysmal bone cyst

–malignant: angiosarcoma

Question 8

What are the adipose tissue tumours?

Answer 8

–benign: lipoma

–malignant: liposarcoma

Question 9

What are the marrow tissue tumours?

Answer 9

–malignant: Ewing’s sarcoma, lymphoma, myeloma

Question 10

What are other tumours?

Answer 10

Benign, are locally destructive and can rarely metastasise - Giant Cell tumours (GCT)

Question 11

What are the tumour like lesions?

Answer 11

Benign: simple bone cyst, fibrous cortical defect

Question 12

What is the incidence of primary bone tumours in the UK?

Answer 12

Osteosarcoma 3 per million popu./yr

Chondrosarcoma 2 ..

Ewing’s tumour 1.5 ..

Malig. fibrous histiocytoma <1 ..

• Osteosarcoma = commonest primary malignant bone tumour in younger patient
• Myeloma = commonest primary malignant “bone” tumour in older patient

Question 13

What is the history of bone tumours?

Answer 13

• Pain
• mass
• Abnormal x-rays - incidental
• Bone Tumours - PAIN

Question 14

What is loked for on examination of the bone cancer?

Answer 14

• General health
• measurements of mass
• location
• shape
• consistency
• mobility
• tenderness
• local temperature
• neuro-vascular deficits

Question 15

What are the investigations for bone cancers?

Answer 15

• Plain x-rays - most useful for bone lesions
• Calcification - synovial sarcoma
• Myositis ossificans - calcification occurs followed by formation of bony tissue within affected muscles
• Phleboliths in haemangioma

Phlebolith is a calcification within a vein

Question 16

What are the signs on X-ray that the tumour is inactive?

Answer 16

Clear margins

Surrounding rim of reactive bone

Cortical expansion can occur with aggressive benign lesions

Question 17

What are the signs on x-ray that the lesion is aggressive?

Answer 17

• 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

So there is a less well defined border, destruction of the cortex and new periosteal bone growth after the lesion has destroyed the cortex.

Question 18

What is the function of CT in the investigation of bone cancer?

Answer 18

• Assessing ossification and calcification
• integrity of cortex
• best for assessing nidus in osteoid osteoma
• Staging - primarily of lungs

Question 19

What is the main purpose of isotope bone scans?

Answer 19

Staging for skeletal mets

Question 20

What might multiple lesions on a bone scan indicate?

Answer 20

•osteochondroma, enchondroma, fibrous dysplasia & histiocytosis

Question 21

What condition are isotope bone scans frequently negative for?

Answer 21

Myeloma

Question 22

What is the point of using an MRI for supsected bone cancer?

Answer 22

Determines the size, extent, anatomical relationships

It is accurate for limits of disease both within and outside bone

Specific for lipoma, haemangioma, haematoma or PVNS

Non-specific for benign vs maignant

Question 23

What are other investigations for bone cancer?

Answer 23

Angiography - replaced by MRI

(used for pseudoaneurysms, AV malformations, embolisation of vascular tumours - renal ABC

PET - may be useful for investigating response to chemo

Biopsy

Question 24

What investigations are needed to be completed before a biopsy?

Answer 24

• Bloods
• X-rays of affected Limb

& Chest

• MRI of lesion
• Bone Scan
• CT Chest, abdo & pelvis

Question 25

What are the cardinal features of malignant primary bone tumours?

Answer 25

* Increasing pain * unexplained pain * Deep-seated boring nature * Night pain * Difficulty weight-bearing * Deep swelling

Question 26

What are some examples of malignant bone tumours?

Answer 26

Osteosarcoma Ewings sarcoma Chondrosarcoma

Question 27

What are the clinical features of bone tumours?

Answer 27

* pain * loss of function * swelling * pathological fracture * joint effusion * deformity * neurovascular effects * systemic effects of neoplasia Pain (increasing, analgesics eventually ineffectvie, not related to exercise, deep boring ache - worse at night)

Question 28

What may indicate loss of function?

Answer 28

–limp –reduced joint movement –stiff back (esp. child)

Question 29

Describe the swelling associated with the tumour

Answer 29

–generally diffuse in malignancy –generally near end of long bone –once reaching noticeable size, enlargement may be rapid –warmth over swelling + venous congestion = active! –pressure effects e.g. intrapelvic

Question 30

What else can cause pathological fractures?

Answer 30

Osteoporosis is the commonest causes many causes, of which primary bone tumour (benign or malignant)

Question 31

How can we determine if the fracture is a pathological fracture?

Answer 31

–minimal trauma + h/o pain prior to # !!

Question 32

WHat is the MRI scan good for showing

Answer 32

* intraosseous (intramedullary) extent of tumour * extraosseous soft tissue extent of tumour * joint involvement * skip metastases * epiphyseal extension Used to determine resection margins

Question 33

What are the available treatment options for bone cancer?

Answer 33

* Goal is to make free of disease * Chemotherapy * Surgery * Radiotherapy * TEAM !!

Question 34

What are suspicious signs of soft tissue tumours?

Answer 34

Deep (deep to deep fascia) Subcutaneous tumours greater than 5 cm Rapid growth, hard, craggy, non-tender

Question 35

When should we be aware of swellings? (these are for soft tissue tumours)

Answer 35

* rapidly growing * hard, fixed, craggy surface, indistinct margins * non-tender to palpation, but assoc. with deep ache, esp. worse at night * BEWARE – may be painless * Recurred after previous excision = NASTY - suspicious of malignant tumour (1° or 2° ) until proven otherwise

Question 36

Which is more common, primary or secondary bone cancer?

Answer 36

* 2° bone tumour 25 x commoner than 1° * bone most common site for 2° after lung and liver

Question 37

What are the common sites of bone cancer in order of frequency?

Answer 37

–vertebrae \> proximal femur \> pelvis \> ribs \> sternum \> skull

Question 38

What are the 7 most common primary cancers which metastasise to bone?

Answer 38

1. LUNG - smoker; CXR, sputum cytology 2. BREAST - commonest; examine! 3. PROSTATE - osteosclerotic 2°; PR, PSA 4. KIDNEY - solitary, vascular; IVP + US, angiography & embolise 5. THYROID - esp. follicular Ca; examine 6. GI TRACT - FOB, endoscopy, Ba studies, markers 7. MELANOMA - examine! [neuroblastoma (of adrenal medulla) - aet. \<4 y]

Question 39

What is prognosis for pathological fracture?

Answer 39

•in general, approx. 50% of patients with pathological fractures will survive \>6 m, & 30% greater than or equal to 1 y

Question 40

What are the prevention mechanisms for pathological fracture?

Answer 40

Early chemotherapy/DXT (deep x-ray therapy) Prophylactic internal fixation Bone cement Embolisation Prophylactic stabilisation of bone should be performed if there is a substantial risk of fracturing. If the risk of fracturing is low, the appropriate treatment is radiotherapy.

Question 41

What is the scoring system used for fracture risk assessment?

Answer 41

Mirel's scoring system

Question 42

Never assume that a lytic lesion, particularly if solitary, is a metastasis

Question 43

What is the failure rate of fixation of pathological fractures or lytic lesion, especially around the hip / proximal femur vs cemented hip prosthesis

Answer 43

Fixation of pathological fractures have a high failure rate, cemented hip prosthesis, either standard or tumour prostheses have a low failure rate Fixation involves the use of nails or plates For all pathological fractures of the long bones, three principal surgical treatment options exist: intramedullary nail, plate, or (endo) prosthesis. Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5367617/

Question 44

What is required during surgery of spinal metastases?

Answer 44

Decompression and stabilisation

Question 45

• Constructs, whether spinal or appendicular, should allow immediate weightbearing and aim to last the lifetime of the patient.

Question 46

•Solitary renal metastases should, where possible, be radically excised.

Question 47

What is the commonest soft tissue tumour?

Answer 47

Lipoma

Question 48

As the soft tissue tumour gets larger - the chances of it being a sarcoma (vs lipoma) gets larger. But it is still more likely to be a lipoma 80% of deep sarcomas are greater than 5cm

Answer 48

Question 49

What are the features of soft tissue tumours?

Answer 49

* painless * mass deep to deep fascia * any mass \>5cm * any fixed, hard or indurated mass * any recurrent mass