Bone and soft tissue tumours Flashcards
What kind of bone tumour is a >50 y/o patient likely to have?
A metastatic bone tumour i.e. secondary malignant tumour
What types of bone tumours can you get?
Benign:
- Osteoid osteoma or osteoblastoma
- These usually form in the proximal femur but also other sites
- Quite rare
Malignant:
- osteosarcoma
What is a Sarcoma?
A malignant tumour arising from connective tissues
- Commonly spreads via the blood to the lungs
Vacular tissue tumours (benign and malignant)
Benign:
- Haemangioma, aneurysmal bone cyst
Malignant:
- Angiosarcoma = rare
Name 3 malignant bone marrow tumours
- Ewing’s sarcoma - childhood cancer
- Lymphoma
- Myeloma
Describe what a simple bone cyst is?
- A benign tumour-like lesion often occuring in children
- They are little fluid-filled holes that form in the cortex of the bone
- They weaken the bone which can lead to fractures (hence why patients often present with a fracture)
- After the fracture heals the cysts tend to disappear
What are the most common primary bone tumours in the UK?
- Osteosarcoma
- Chondrosarcoma - malignant cartilage tumour
- Ewing’s tumour
What is the commonest primary malignant bone tumour in younger patients?
Osteosarcoma
What is the commonest primary malignant “bone” tumour in older patient?
Myeloma
Typical presentation of patient with a bone tumour?
- PAIN - pain at rest/activity related/at night, deep-seated and boring pain
- A mass if progressed - malignant mass would be hard, craggy, immobile/fixed etc
- Abnormal x-ray - often incidental finding
What are some common characteristics of pain associated with bone tumours?
- Pain may be activity related – this might be due to weakening of the bone and therefore any stress placed on the bone puts it at risk of fracture. This is associated with malignant tumours and also benign tumours but only if they are large enough
- Progressive pain at rest & night
Osteoid Osteoma
Benign bone tumour
- Tiny bone forming tumours called ‘nidus’’ - (tumour tissue in centre with bone surrounding it)
- These can create intense pain at night – until the nidus is removed that pain will continue
What sorts of things should you look out for during an examination of a patient with unusual mass? (9)
- General health – are they fit and well?
- Measurements of mass
- Location of mass
- Shape of mass
- Consistency – hard mass is bad news
- Mobility – fixed to deeper tissue or the skin above it?
- Tenderness
- Local temperature change – indicating vascularity
- Neuro-vascular deficits – changes in sensation, power etc due to invasion of nerves etc
During examination, what signs indicate that it might be more sinister i.e. a malignant bone tumour?
- Rapidly growing mass
- Mass will be hard, craggy, fixed, indistinct margins
- Non-tender to palpation but associated with deep ache
What is the best imaging tool for looking at bone lesions?
X-ray
Name some lesions that are associated with bone tumours that you should look out for on an x-ray (3)
- Calcification - synovial sarcoma (calcification of the thickened synovium)
- Myositis ossificans - bone tissue forms inside muscle or other soft tissue after an injury - as a result of trauma, not a tumour
- Phleboliths in haemangioma - small areas of calcifications in blood vessel tumours
What features would you expect to see on an x-ray of a benign bone tumour?
- Clear margins
- Surrounding rim of reactive bone
- Cortical expansion can occur with aggressive benign lesions
This x-ray shows a benign tumour on the front of the tibia. Likely to be a benign cyst. Due to weakening of the bone, a fracture has appeared (likely after this fracture heals the bone cyst will disappear). If the cyst is still present after the fracture has healed, surgery may be recommended in order to prevent another fracture.
What features would you expect to see on an x-ray of an aggresive bone tumour?
- Less well defined zone of transition between lesion and normal bone (permeative growth)
- If there is cortical destruction = malignancy
- Periosteal reactive new bone growth occurs when the lesion destroys the cortex.
- Codman’s triangle, onion-skinning
- Sunburst pattern - Tumour bursting out of distal femur
X-ray shows an Osteosarcoma of the distal femur. You can also see the sunburst pattern clearly.
When is CT imaging used?
- Primarily used for staging of secondary metastases (i.e. the lungs)
- Assessing ossification and calcification
- Assessing the integrity of cortex
- Best for assessing nidus in osteoid osteoma – location etc
What are isotope bone scans used for? (4)
- Staging for skeletal metastasis as you can see how many metastases there are on a single scan
- Also good for multiple benign lesions - osteochondroma, enchondroma, fibrous dysplasia & histiocytosis
- Frequently negative in Myeloma
- Benign also demonstrate increased uptake
How does an isotope bone scan work?
- Inject isotope into patient
- The isotope is taken up by active bone and is laid down in bone structure as a calcium substitute.
- Increased uptake where there is increased bone turnover (tumour)
- But there can also be increased uptake in benign lesions
Why is MRI the best imaging technique for primary bone and soft tissue tumours?
- Allows you to see size, extent of masses and the anatomical relationships i.e the relationship between a tumour and surrounding blood vessels, nerves etc
- Extent - allows you to see intraosseous (intramedullary) extent of tumour and extraosseous extent i.e how far it extends into soft tissue
- Specific for Lipoma, haemangioma, haematoma or PVNS – they have specific signals on MRI so you know definite diagnosis
- Can show if there is any joint involvement
- However, it’s not very good at differentiating between benign vs. malignant
What is the main role of Angiography in terms of bone tumour management nowadays?
- Imaging prior to tumour embolisation – tumours with a high vascularity (i.e. renal tumour secondaries to bone) will be embolised prior to surgery
- Embolisation shuts down the blood supply to a tumour reducing blood loss during surgical resection
What is the best way to differentiate between a benign or malignant tumour?
Biopsy - needle core or open
What are the cardinal features of a malignant bone tumour? i.e. the major clinical signs/symptoms by which a diagnosis is made.
- Increasing pain
- Unexplained pain
- Deep-seated boring nature
- Night pain
- Difficulty weight-bearing
- Deep swelling
Osteosarcoma:
Incidence, symptoms and treatment
M>F, 10-30 y/o - common in this age group
Most common site = the distal femur and proximal tibia
Symptoms:
- pain
- loss of function – due to discomfort. May have a limp or stiff back (red flag in child/young person)
- swelling i.e tumour - generally diffuse in malignancy
- pathological fracture - primary bone tumour (benign or malignant) is actually quite a rare cause
- joint effusion
- deformity
- neurovascular effects
- systemic effects of neoplasia, weight loss, low grade temp, loss of appetite
Treatment:
Goal is to make free of disease and improve QOL
- Chemo – shrink tumour
- Surgery – excise tumour
- May do radiotherapy
What red flag signs should you be wary of in regards to any tumour/swelling?
If the swelling is:
- 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
It is likely a malignancy
Examples of soft tissues (9)
- Muscles
- Tendons
- Ligaments
- Fascia
- Nerves
- Fibrous tissues
- Fat
- Blood vessels
- Synovial membranes
What are the most common sites for secondary metastatic tumours?
- Lung
- Liver
- Bone
Which sites in the bony skeleton do secondary tumours that spread to bone most commonly affect? (6)
- Vertebrae
- Proximal femur
- Pelvis
- Ribs
- Sternum
- Skull
What are the most common primary cancers that metastasise to bone? (7)
- Lung
- Breast
- Prostate
- Kidney
- Thyroid
- GI tract
- Melanoma
How are pathalogical fractures prevented?
- Identify them through things like routine bone scans
- Early chemo i.e. in breast cancer to reduce number of secondaries
- Radiotherapy where secondaries are identified
- When pain is increasing – real risk of fracture – so if we see a tumour >2.5 cm on an x-ray then we know that will often lead to fracture – prophylaxis treatment – fixation to stop the fracture
- Often add bone cement to increase stability
What scoring system is used to identify patients who would benefit from prophylactic fixation due to having a high risk of pathological fracture?
Mirel’s scoring system
- Looks at site, pain, lesion and size
- If score is 8 or more – recommend prophylaxis fixation before radiotherapy
What must be done before a surgical procedure to remove a tumour?
Embolisation of the tumour and then a wait of 48 hours before surgery to prevent catastrophic bleeding
Why is size so important in differentiating between a benign or malignant soft tissue tumour?
- If the swelling is <5cm it is more likely to be a lipoma (benign)
- Anything >5cm is likely to be a sarcoma (malignant)
- So if it is a large, deep seated swelling – you can be quite sure that it is a sarcoma
Common features of a malignant soft tissue tumour
- Painless
- Mass deep to deep fascia
- Any mass >5cm
- Any fixed, hard or indurated mass
- Any recurrent mass
