Benign Bone Tumours Flashcards
What is an osteochondroma?
Bony outgrowth on external surface with a cartilaginous cap
Presentation of osteochondroma?
No problems apart from local pain
Risk of osteochondroma?
1% risk of malignant transformation
How is multiple osteochondromata inherited?
Autosomal dominant hereditary disorder
What is enchondroma?
Intramedullary & usually metaphyseal cartilaginous tumour
What failure is associated with enchondroma?
Failure of normal enchondral ossification at the growth plate
Symptoms of enchondroma?
Usually asymptomatic
-can weaken bone (pathological fracture)
Where are enchondromas usually?
Femur
Humerus
Tibia
Small bones of Hand & Feet
What does an enchondroma lesion usually look like?
Usually lucent but can undergo mineralization- Patchy sclerotic appearance
Treatment of enchondroma?
Fracture healed and risk of impending fracture- curettage & filled with bone graft
What is curettage?
Bone scraped out
What is simple bone cyst?
Single cavity, benign fluid filled cyst
What is the probable cause of a simple bone cyst?
Probably a growth defect from the physis
Presentation of simple bone cyst?
Can be asymptomatic & an incidental finding on x-ray
-Can cause weakness resulting in pathological fracture
Treatment of a simple bone cyst?
Curettage and bone grafting +/- stabilization
Another term for simple bone cyst?
Unicameral bone cyst
What is an aneurysmal bone cyst?
Lots of blood/serum filled chambers
What are aneurysmal bone cysts due to?
Small arteriovenous malformation
Where do aneurysmal bone cysts appear?
In metaphyses of many different long bones, flat bones
(Ribs, skulls) and vertebral bodies
Presentation of aneurysmal bone cysts?
Locally aggressive
- Cortical expansion & destruction
- Painful, pathological fracture
Treatment of aneurysmal bone cysts?
Curettage & grafting/bone cement
Where do giant cell tumours affect?
Metaphyseal region
-Involve epiphysis & can extend to the subchondral bone adjacent to the joint
-Knee, distal radius, also other long bones: pelvis, spine
Presentation of giant cell tumour?
- Painful
- May cause pathological fracture
What does a giant cell tumour look like on x-ray?
Soap bubble appearance
Where do 5% of giant cell tumours metastasize to?
The lung
What type of cell do giant cell tumours consist of?
Multi-nucleate giant cells
Treatment of giant cell tumours?
Intralesional excision with phenol, bone cement or liquid nitrogen
-Destroy remaining tumour material & reduce risk of recurrence
Treatment of very aggressive lesions with cortical destruction?
May need replacement
When does fibrous dysplasia present?
Adolescence
What causes fibrous dysplasia?
Genetic mutation
What is fibrous dysplasia?
Scar Lesions in fibrous tissue & immature bone
Meaning of monostotic?
Affects 1 bone
Meaning of polyostotic?
Affects more than one bones
Presentation of fibrous dysplasia?
- Angular deformities
- Wider bone
- Thickened cortices
- Stress fractures can occur
- Shepherd’s crook deformity (proximal femur)
Treatment of fibrous dysplasia?
- Biphosphonates may reduce pain
- Pathologic fractures should be stabilized with internal fixation & cortical bone grafts
- Simple intralesional excision has a high recurrence rate
What is osteoid osteoma?
Small nidus of immature bone surrounded by an intense sclerotic halo
When does osteoid osteoma present?
Adolescence
Common sites of osteoid osteoma?
Proximal femur
Diaphysis of long bones
Vertebrae
Clinical features of osteoid osteoma?
Intense constant pain (worse at night due to intense inflammatory response)
Treatment of osteoid osteoma?
May resolve spontaneously over time
Some cases require CT quidded radiofrequency ablation/ en bloc excision
