Benign Bone Tumours Flashcards
What are benign tumours?
neoplastic developmental traumatic infectious or inflammatory
what is a malignant tumour?
primary bone tumours are rare
metastases are common
sarcoma=malignant
What is an osteochondroma?
benign
bony outgrowth on external surface with a cartilaginous cap
very small risk 1% of malignant transformation - may require excisional biopsy
can be solitary
multiple osteochondroma - an autosomal dominant hereditary disorder (higher malignant potential)
observe closely may need to excise
how does osteochondroma present?
usually in adolescence near the knee (distal femur/ proximal tibia) usually a painless hard lump can get symptoms with activity (pain from tendons numbness from nerve compression
what is enchondroma?
intermedullary usually metaphysical cartilaginous tumour
caused by a failure of normal enchondral ossification at the growth plate
lesion is usually lucent but can go through mineralisation with a patchy sclerotic appearance
how does enchondroma present?
usually asymptomatic but can weaken the bone causing a pathological fracture
- once the fracture has healed there is a rick of an impeding fracture they can be scraped out (curettage) and filled in with bone graft to strengthen
femur, humerus, tibia and small bones of the hands &/or feet
what is a simple bone cyst (unicameral bone cyst)?
a single cavity benign fluid filled cyst in a bone
probably a growth defect from the physis
how does a simple bone cyst present?
can be asymptomatic (can be incidental finding)
usually in a child/young adult
can cause weakness leading to pathological fracture
may need curettage and bone grafting +/- stabilisation
what is an aneurysmal bone cyst?
lots of blood/serum filled chambers - may be seen on x-ray
due to a small arteriovenous malformation
occur in the metaphyses of many different long bones, flat bones (skull and ribs) and vertebral bodies
how does an aneurysmal bone cyst present?
usually painful, risk f pathological fracture
locally aggressive lesion causing cortical expansion/destruction
curettage and grafting/use of bone cement to treat
what is a giant cell tumour?
can be a locally aggressive tumour
metaphysal region - involve the epiphysis and can extend to the subchondral bone adjacent to the joint
around the knee distal radius - also other long bones, pelvis, spine
after the physis has fused and are locally destructive destroying the cortex
the cause is unknown but they consist of multi-nucleate giant cells
how does a giant cell tumour present?
painful
may cause pathological fracture
X-ray: ‘soap bubble’ appearance
5% can metastasize to the lung
how is a giant cell tumour managed?
intralesional excision with phenol, bone cement or liquid nitrogen - destroy remaining tumour material and reduce risk of reoccurrence
very aggressive lesions with cortical destruction may need joint replacement
what is fibrous dysplasia?
occurs in adolescence
caused by a genetic mutation which leads to lesions in fibrous tissue and immature bone
monostotic= affects 1 bone
polystotis = affects more bones
What is effect of defective mineralization in fibrous dysplasia?
angular deformities wider bone thickened cortices stress fractures can occur Shepherd's crook deformity - proximal femur
intense increase in uptake during development but then the lesion usually becomes inactive
How is fibrous dysplasia treated?
bisphosphate - may reduce pain
pathologic fractures should be stabilised with internal fixation and cortical bone grafts
simple intralesional excision has a high recurrence rate
what is osteoid osteoma?
small nidus (infection) of immature bone surrounded by an intense sclerotic halo occurs in adolescence
how does osteoid osteoma present?
in the proximal femur
diaphysis of long bones, vertebrae
intense constant pain - worse at night due to intense inflammatory response
NSAIDs greatly relieve the pain
how is osteoid osteoma managed?
bone scan confirms diagnosis
may resolve spontaneously over time
some cases require CT guided radiofrequency ablation/ en bloc excision
what other benign growth can present as a lytic lesion (bone lesion) of bone?
Brodie’s abscess (subacute osteomyelitis) and hyperthyroidism (brown tumours)
