cortex module Flashcards
what is the most common benign bone tumour
The commonest is an osteochondroma which produces a bony outgrowth on the external surface with a cartilaginous cap.
what is an enchondroma
An intramedullary and usually metaphyseal cartilaginous tumour caused by failure of normal enchondral ossification at the growth plate.
what is a simple bone cyst (aka unicameral bone cyst)
A single cavity benign fluid filled cyst in a bone. They may be asymptomatic and an incidental finding on xray (usually a child or young adult) however they can cause weakness leading to pathological fracture. Again treatment with curettage and bone grafting with or without stabilization may be required.
what is an aneurysmal bone cyst
Contains lots of chambers which are filled with blood or serum. They are thought to be due to a small arteriovenous malformation. They can occur in the metaphyses of many different long bones, flat bones (ribs, skull) and vertebral bodies. The lesion is locally aggressive causing cortical expansion and destruction and is usually painful. Again there is a risk of pathological fracture. Treament is again with curettage and grafting or the use of bone cement.
what is a giant cell tumur
GCTs most commonly occur around the knee and in the distal radius but can occur in other long bones, the pelvis and the spine. They occur after the physis has fused and are locally destructive destroying cortex. They are painful and may cause pathological fracture. The aetiology is unknown but as the name suggests histologically they consist of muli‐nucleate giant cells. On Xray they have a characteristic “soap bubble” appearance. Although they are considered benign, 5% can metastasize to the lung with benign pulmonary GCT. Treatment is 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
Disease of a bone usually occurring in adolescence where a genetic mutation results in lesions of fibrous tissue and immature bone. It can affect one bone (monostotic) or more (polyostotic). Defective mineralization may result in angular deformities and the affected bone is wider with thinned cortices.
what is an osteoid osteoma
small nidus of immature bone surrounded by an intense sclerotic halo. They most commonly occur in adolescence and common sites include the proximal femur, the diaphysis of long bones and the vertebrae. The predominant clinical feature is intense constant pain, worse at night due to the intense inflammatory response. This pain is greatly relieved by NSAIDs. The lesion may be seen on xray however bone scan (intense local uptake) and CT can confirm the diagnosis. The lesion may resolve spontaneously over time but some cases may require CT guided radiofrequency ablation or en bloc excision.
metastatic cancer of the bone tends to produce what type of pain
constant pain which may be severe and is usually worse at night
what do malignant primary bone tumours show on an x-ray
aggressive and destructive signs including cortical destruction, a periosteal reaction, new bone formation and extension into the surrounding tissue
what is chondrosarcoma
A cartilage producing primary bone tumour and is less common and less aggressive than osteosarcoma. It tends to occur in an older age group (mean age 45). They can be very large and are slow to metastasize. They tend to be found in the pelvis or proximal femur. The prognosis is dependant on the histological grade with the majority being low grade. They are not radiosensitive and unresponsive to adjuvant chemotherapy thus far.
what are fibrosarcoma and malignant fibrous histiocytoma
Fibrous malignant primary bone tumours which tend to occur in abnormal bone (bone infarct, fibrous dysplasia, post irradiation, Paget’s disease). Fibrosarcona tends to affect adolescents or young adults.
what is Ewings sarcoma
A malignant tumour of primative cells in the marrow. It is the 2nd most prevalent primary bone tumour and has the poorest prognosis. Most cases occur between the ages of 10 and 20. It may be associated with fever, raised inflammatory markers and a warm swelling and may be misdiagnosed as osteomyelitis. It tends to be radio‐ and chemo‐sensitive.
what investigations are carried out for primary bone tumours
- bone scan and CT chest
- MRI and CT are good for determining the local extent of of the tumour and the involvement of muscles, nerves and vessels
- biopsy is required for histological diagnoses
what is the treatment for a primary bone tumour
- surgery to remove the tumour and surrounding tissue to reduce the risk of recurrence
- chemotherapy
- radiotherapy
what is a lymphoma (a cancer of round cells of the lymphocytic system/macrophages)
can occur as a primary bone tumour (as Non Hodgkins Lymphoma) from the marrow or lymphoma (any type) can metastasize to bone (in 20% of cases). Primary lymphoma of bone tends to affect the pelvis or femur and treatment is with surgical resection. With metastatic lymphoma lymphadenopathy or splenomegaly may be present and treatment is chemotherapy and radiotherapy. Survival of metastatic lymphoma is usually less than 2 years.