Basic Science Flashcards
Name all the benign bone tumours.
Osteochondroma, enchondroma, simple bone cyst, aneurysmal bone cyst, giant cell tumour, fibrous dysplasia, osteoid osteoma.
What is an osteochondroma?
Bony outgrowth on external surface with cartilaginous cap.
What are possible problems associated with osteochondroma?
Very small risk of malignant transformation and can produce local pain.
What is an enchondroma?
An intramedullary and usually metaphyseal cartilaginous tumour caused by failure of normal enchondral ossification at the growth plate.
What are the problems associated with enchondroma?
Usually asymptomatic but can weaken the bone resulting in pathological fracture.
How may an enchondroma causing problems be treated?
Scraped out (curettage) and filled with bone graft to strengthen the bone.
What are simple bone cysts and how are they caused?
Single cavity benign fluid filled cyst in bone. Probably a growth defect from the physis and are therefore metaphyseal in long bones.
What are aneurysmal bone cysts are how are they caused?
Lots of chambers which are filled with blood or serum. Arteriovenous malformation.
What problems can aneurysmal bone cysts cause and how are they treated?
Lesions locally aggressive causing cortical expansion and destruction and is usually painful, also risk of pathological fracture. Again curettage and grafting/bone cement.
What problems can giant cell tumours cause?
Locally destructive destroying cortex, they are painful and may cause pathological fracture.
Where can giant cell tumours metastasise and are they benign?
5% can metastasise to the lung, they are benign.
What is the treatment for giant cell tumours?
Intralesional excision with use of phenol, bone cement or liquid nitrogen to destroy remaining tumour material and reduce the risk of recurrence. Very aggressive lesions with cortical destruction may need joint replacement.
What is fibrous dysplasia and when does it usually occur?
Genetic mutation results in lesions of fibrous tissue and immature bone, usually occurs in adolescence.
What is the treatment for fibrous dysplasia?
Bisphosphonates to reduce pain, pathological fractures stabilised with internal fixation and cortical bone grafts to improve strength (simple intralesional excision alone has very high recurrence rate).
What is an osteoid osteoma and when does it commonly occur?
A small nidus of immature bone surrounded by an intense sclerotic halo. Most commonly occur in adolescence.
What is the prominent clinical feature of osteoid osteoma?
Constant pain, worse at night due to intense inflammatory response.
What is the treatment for osteoid osteoma?
May resolve spontaneously over time, but may required CT guided radiofrequency ablation or en bloc excision.
What is the symptom of metastatic cancer which has spread to bone?
Constant pain which may be severe and usually worse at night.
What aggressive and destructive signs do primary bone tumours show on X-ray?
Cortical destruction, periosteal reaction (raised periosteum production new bone), new bone formation (sclerosis as well as lysis from destruction) and extension into surrounding soft tissue envelope.
In order of frequency, where does osteosarcoma usually affect?
Knee, proximal femur, proximal humerus and pelvis.
What are all the malignant bone tumours?
Osteosarcoma, chrondosarcoma, fibrosarcoma, malignant fibrous histiocytoma, Ewing’s sarcoma.
What primary bone tumour has the worst prognosis?
Ewing’s sarcoma.
What tumours metastasise to bone in order of frequency?
Breast, prostate, lung, renal cell, thyroid.
What is the similar end result of osteochondritis and avascular necrosis (AVN)?
Area of bone undergoes localised necrosis as a result of ischaemia from a reduction in blood supply.
