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
