Bone Tumours Flashcards
Commonest benign bone tumour?
Osteochondroma
X-ray appearance of osteochondroma?
Bony spur with cartilaginous cap
X-ray appearance of osteoid osteoma?
Sclerotic halo around immature bone
Characteristic pain in osteoid osteoma?
Severe, worse at night, relieved by NSAIDs
Which (benign) tumour has a 1% risk of malignant transformation?
Osteochondroma
Commonest site of osteochondroma?
Knee
Benign tumour that classically affects small tubular bones of the hands and feet?
Enchondroma
Scenario: fractured clavicle in an 8 year old due to FOOSH. On x-ray, there is a lucent lesion in the middle 1/3 of the clavicle with a smooth edge where it meets the more normal looking bone. There is mild expansion of the cortex.
What’s caused this pathological fracture?
Simple bone cyst
Treatment of a simple bone cyst?
Curettage and bone graft
What’s an aneursymal bone cyst filled with?
Blood / plasma
What is fibrous dysplasia?
Normal bone and marrow is replaced with fibrous tissue - the resultant bone is weak and prone to expansion.
What cellular abnormality occurs to cause fibrous dysplasia?
problem in G protein signalling
What causes shepherd crooks deformity?
which condition, and which bone is affected
Proximal femur involvement in fibrous dysplasia
Treatment of fibrous dysplasia?
Bisphosphonates plus internal fixation of pathological fractures
Other conditions can present with a lytic bone lesion.
These presentations include Brodie’s abscess and Brown’s tumour - what conditions are these lesions related to?
Brodie’s abscess = subacute osteomyelitis
Brown’s tumour = hyperparathyroidism
Buzzword / classic sign for giant cell tumour on x-ray?
Soap bubble appearance
Where can giant cell tumour spread to?
Lungs, causing benign pulmonary giant cell tumour
What’s the chromosomal translocation associated with giant cell tumours?
Translocation between chromosome 1 and 2
Most commonly location for a giant cell tumour?
Knee and distal radius.
Tends to be metaphyseal and epiphyseal. They are locally destructive to the cortex
Histology of giant cell tumours?
many multi-nucleated giant cells
What’s the difference between pain in osteoblastoma and osteoid osteoma?
Osteoblastoma isn’t worse at night
Note both conditions are clinically and histologically similar, though osteoblastoma is larger
Where does chondroma develop from (embryologically)?
Notochord (which forms the spinal cord in foetuses)
What age group is usually affected by chondoma?
Which bone is affected?
40-60 year olds
Any part of the spine (tumour develops from notochord)
x-ray appearance of an aneursymal bone cyst?
Multiple chambers visible
