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
