Bone Tumours Flashcards
How can bone tumours be divided?
Into primary and secondary tumours.
The primary tumours arise from cells which constitute the bone and can be divided further into benign and malignant types.
Epidemiology of bone tumours
Metastatic bone tumours make the most of the disease burden.
Primary bone tumours are relatively rare with an overall prevalence of < 1% in the UK.
In children and adolescents it is more common (5% of all cancers)
Where does metastatic bone cancer come from?
Renal
Thyroid
Lung
Prostate
Breast
Most common site for a bony metastases is the spine
How is metastatic bone disease usually treated?
Systemic therapies and often palliative.
It is rarely treated surgically.
Prophylactic nailing of certain long bones can be done if there is a high risk of pathological fractures.
Risk factors for primary bone cancer.
RB1 and p53 are associated with increased risk of osteosarcomas.
TSC1 and TSC2 mutations (tuberous sclerosis) are associated with an increased risk of chondromas during childhood.
Previous exposure to radiation or alkylating agents in chemotherapy
Benign bone conditions like Paget’s disease and fibrous dysplasia.
Clinical features
Main symptoms of a primary bone tumour is pain
It is not associated with movement
Worse at night (red flag)
Mass may be palpable
If the patient presents with a fracture without hx of trauma a bone tumour may be suspected as well.
Dx
Osteomyelitis
Multiple myeloma
Metabolic bone disease
Pathological fracture
Explain osteoid osteoma.
Arise from osteoblasts, often around the 10-20 yo.
More common in males and are typically small tumours (<2cm)
Found usually around the metaphysis of long bones like proximal femur or tibia.
Clinical presentation of osteoid osteoma.
Localised progressive pain worse at night.
NSAIDs usually makes it better
Localised swelling, tenderness or limping might occur as well.
X-ray findings of osteoid osteoma.
Show a small mass commprised of a radiolucent nidus with a rim of reactive bone.
Management of osteoid osteoma.
Conservatively through serial radiological imaging every 4-6 months.
If there is severe pain that may warrant surgical resection.
Overall there is a good prognosis and they resolve spontaneously.
Explain osteochondroma
AKA exostoses are benign bony tumours.
They form as an outgrowth from the metaphysis of long bones and have a cartilaginous cap.
Most develop in males in their 10s to 20s.
Clinical presentation of osteochondroma.
Most are detected incidentally and usually asymptomatic and slow growing.
Can cause deformities or impinge on nerves they grow large enough.
X-ray findings of osteochondroma
Pedunculated bony outgrowth from metaphysis pointing away from the joint.
How are osteochondromas managed?
Conservatively through serial radiological imaging every 4-6 months.
Those with significant deformity or neurological symptoms may warrant surgical resection.
Explain chondromas.
Arise from chondroblasts within the medullary cavity of the bones.
They present in 20-50 years olds
Most commonly affect the long bones of the hands, femur and humerus.
Clinical presentation of chondromas.
Asymptomatic
Can present as pathological fracture
X-ray findings of chondromas.
Well circumscribed oval lucency with intact cortex.
Management of chondromas.
Depends on size and clinical features.
Most asymptomatic -> observed.
Large or symptomatic -> removal with curettage and bone grafting as there is a small risk of transformation into malignant chondrosarcoma.
Explain giant cell tumour
AKA osteoclastomas.
Arise from multinucleated giant cells and stromal cells.
Occur in patients 20-30 yo
Affects the epiphysis of long bones most commonly.
Clinical presentation of osteoclastomas.
Pain
Swelling
Limitation of joint movement
X-ray findings of osteoclastomas
Eccentric lytic area
Soap bubble appearance
Management of osteoclastoma
Surgical resection
Potential need for bone grafting or reconstruction
Explain osteosarcoma
Most common malignant primary bone tumour.
Bimodal age of onset -> 10-14 yo or in >65 yrs
Most commonly found at the metaphysis of the distal femur or proximal tibia.
Clinical presentation of osteosarcoma
Localised constant pain and a tender soft tissue mass
X-ray findings of osteosarcoma
Medullary and cortical bone destruction
Significant periosteal reactions
Codman’s triangle or sunburst pattern
Diagnosis of osteosarcoma
By tissue biopsy
Management of osteosarcoma
Aggressive surgical resection with systemic chemotherapy
They commonly metastasise to the lung and bone
Explain Ewing’s sarcoma
Paediatric malignancies that are more common in males and arise from primitive poorly differentiated neuroectodermal cells.
They commonly affect the diaphysis of long bones.
It is associated with genetic translocation of chromosomes 11 and 22
Clinical presentation of Ewing’s sarcoma.
Painful and enlarging mass with tenderness and warmth
This means that is can initially be mistaken as osteomyelitis.
X-ray findings
Lytic lesion with periosteal reactions
Produces layers of reactive bone leading to characteristic onion skin appearance
Management of Ewing’s sarcoma
Neoadjuvant chemo followed by surgical excision.
Radiation may be considered for local control in patients with unresectable primary tumours.
Explain chondrosarcoma
Malignant tumours of the cartilage
Arise as primary lesions but can also be from benign chondromas.
Age of onset is 40-60 years of age typically affecting the axial skeleton such as pelvis, shoulder and ribs.
Clinical presentation of chondrosarcoma.
Painful and enlarging mass
X-ray findings of chondrosarcom
Lytic lesions with calcifications
Cortical remodelling
Endosteal scalloping
Management of chondrosarcoma
Intralesional curettage
Wide en-bloc local excision is preferred for intermediate and high grade lesions.
Ix
X-ray should be done and then discussed in an appropriate multidisciplinary team before further investigations are arranged.
Most suspected cases will need MRI imaging as well to assess the lesion and soft tissue involvement.
CT can be useful for assessment of cortical involvement.
Bone biopsy may be required for definitive diagnosis
X-ray findings of bone tumours.
Benign => Often sharp and well defined.
Lacks soft tissue involvement and no cortical destruction
Malignant => Often poorly defined with rough borders, involving soft tissues and have cortical destruction.
What staging system is most commonly used for orthopaedic tumours?
Enneking staging system
Explain Enneking staging system of benign tumours
Based on radiographic characteristics
Latent - Well-demarcated borders that grow slowly, can heal spontaneously and have negligible recurrence after intracapsular resection
Active - Well defined borders but may show cortical thinning.
Negligible recurrence after marginal resection.
Aggressive - Indistinct borders and their growth is not limited by natural barriers.
High recurrence rates after intracapsular or marginal resection.
Explain Enneking staging system of malignant tumours.
