Define sarcoma
Malignant tumours arising from connective tissue
What is the spread of sarcomas?
- Spread along fascial planes
- Haematogenous spread to lungs
- Rarely to regional lymph nodes (rhabdomyosarcomas, epithelioid sarcomas & synovial sarcomas)
How common are benign and malignant tumours of the bone?
- benign tumours of skeleton common
- malignant tumours of skeleton RARE
- bony secondaries very common
- bone tumour in patient >50y likely to be metastatic
What are the bone forming tumours?
–benign: osteoid osteoma, osteoblastoma
–malignant: osteosarcoma
What are the cartilage forming tumours?
–benign: enchondroma, osteochondroma
–malignant: chondrosarcoma
What are the fibrous tissue tumours?
–benign: fibroma
–malignant: fibrosarcoma, malignant fibrous histiocytoma (MFH)
What are the vascular tissue tumours?
–benign: haemangioma, aneurysmal bone cyst
–malignant: angiosarcoma
What are the adipose tissue tumours?
–benign: lipoma
–malignant: liposarcoma
What are the marrow tissue tumours?
–malignant: Ewing’s sarcoma, lymphoma, myeloma
What are other tumours?
Benign, are locally destructive and can rarely metastasise - Giant Cell tumours (GCT)
What are the tumour like lesions?
Benign: simple bone cyst, fibrous cortical defect
What is the incidence of primary bone tumours in the UK?
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
What is the history of bone tumours?
- Pain
- mass
- Abnormal x-rays - incidental
- Bone Tumours - PAIN
What is loked for on examination of the bone cancer?
- General health
- measurements of mass
- location
- shape
- consistency
- mobility
- tenderness
- local temperature
- neuro-vascular deficits
What are the investigations for bone cancers?
- 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
What are the signs on X-ray that the tumour is inactive?
Clear margins
Surrounding rim of reactive bone
Cortical expansion can occur with aggressive benign lesions
What are the signs on x-ray that the lesion is aggressive?
- 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.
What is the function of CT in the investigation of bone cancer?
- Assessing ossification and calcification
- integrity of cortex
- best for assessing nidus in osteoid osteoma
- Staging - primarily of lungs
What is the main purpose of isotope bone scans?
Staging for skeletal mets
What might multiple lesions on a bone scan indicate?
•osteochondroma, enchondroma, fibrous dysplasia & histiocytosis
What condition are isotope bone scans frequently negative for?
Myeloma
What is the point of using an MRI for supsected bone cancer?
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
What are other investigations for bone cancer?
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
What investigations are needed to be completed before a biopsy?
- Bloods
- X-rays of affected Limb
& Chest
- MRI of lesion
- Bone Scan
- CT Chest, abdo & pelvis
What are the cardinal features of malignant primary bone tumours?
- Increasing pain
- unexplained pain
- Deep-seated boring nature
- Night pain
- Difficulty weight-bearing
- Deep swelling
What are some examples of malignant bone tumours?
Osteosarcoma
Ewings sarcoma
Chondrosarcoma
What are the clinical features of bone tumours?
- 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)
What may indicate loss of function?
–limp
–reduced joint movement
–stiff back (esp. child)
Describe the swelling associated with the tumour
–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
What else can cause pathological fractures?
Osteoporosis is the commonest causes
many causes, of which primary bone tumour (benign or malignant)
How can we determine if the fracture is a pathological fracture?
–minimal trauma + h/o pain prior to # !!
WHat is the MRI scan good for showing
- intraosseous (intramedullary) extent of tumour
- extraosseous soft tissue extent of tumour
- joint involvement
- skip metastases
- epiphyseal extension
Used to determine resection margins
What are the available treatment options for bone cancer?
- Goal is to make free of disease
- Chemotherapy
- Surgery
- Radiotherapy
- TEAM !!
What are suspicious signs of soft tissue tumours?
Deep (deep to deep fascia)
Subcutaneous tumours greater than 5 cm
Rapid growth, hard, craggy, non-tender
When should we be aware of swellings? (these are for soft tissue tumours)
- 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
Which is more common, primary or secondary bone cancer?
- 2° bone tumour 25 x commoner than 1°
- bone most common site for 2° after lung and liver
What are the common sites of bone cancer in order of frequency?
–vertebrae > proximal femur > pelvis > ribs > sternum > skull
What are the 7 most common primary cancers which metastasise to bone?
- LUNG - smoker; CXR, sputum cytology
- BREAST - commonest; examine!
- PROSTATE - osteosclerotic 2°; PR, PSA
- KIDNEY - solitary, vascular; IVP + US, angiography & embolise
- THYROID - esp. follicular Ca; examine
- GI TRACT - FOB, endoscopy, Ba studies, markers
- MELANOMA - examine!
[neuroblastoma (of adrenal medulla) - aet. <4 y]
What is prognosis for pathological fracture?
•in general, approx. 50% of patients with pathological fractures will survive >6 m, & 30% greater than or equal to 1 y
What are the prevention mechanisms for pathological fracture?
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.
What is the scoring system used for fracture risk assessment?
Mirel’s scoring system
Never assume that a lytic lesion, particularly if solitary, is a metastasis
What is the failure rate of fixation of pathological fractures or lytic lesion, especially around the hip / proximal femur vs cemented hip prosthesis
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/
What is required during surgery of spinal metastases?
Decompression and stabilisation
• Constructs, whether spinal or appendicular, should allow immediate weightbearing and aim to last the lifetime of the patient.
•Solitary renal metastases should, where possible, be radically excised.
What is the commonest soft tissue tumour?
Lipoma
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
What are the features of soft tissue tumours?
- painless
- mass deep to deep fascia
- any mass >5cm
- any fixed, hard or indurated mass
- any recurrent mass
