Bone Tumours Flashcards
What is the most common benign bone tumour?
Where do they typically occur?
Osteochondroma
Typically occurs around the epiphysis of long bones and are most common at the knee

Do osteochondromas cause problems/pain?
Typically they don’t, although they may cause localised pain
May require surgical excision if becoming progressively larger
Multiple osteochondromas may point to an underlying genetic condition
What are the different regions of a long bone?
Epiphysis (at the end)
Metaphysis (around the end of the shaft)
Diaphysis (the shaft)
What are enchondromas and where do they classically appear?
Intramedullary cartilagenous tumour, typically occuring ing the metaphysis
Are usually lucent but can undergo mineralisation to develop a patchy sclerotic appearance
Classically appear in the small tubular bones of the hands and feet
Do enchondromas cause problems?
Most are found incidentally and are usually asymptomatic
Can potentially result in weakening of the bones, leading to fractures

What is the difference between a simple bone cyst and an aneurysmal bone cyst?
Simple bone cyst - solitary unicystic, fluid-filled neoplasm found in the metaphysis of long bones, although can also occur in the talus and calcaneus
Aneurysmal bone cyst - contains lots of chambers that are filled with blood or serum, thought to be due to small arteriovenous malformation. Can occur in long bones, flat bones and vertebral bodies
Simple bone cysts are usually (painless/painful)
Aneurysmal bone cysts are usually (painless/painful)
Simple - painless
Aneurysmal - painful, due to being a locally aggressive lesion causing cortical expansion and destruction
Where do Giant Cell Tumours typically occur?
Are they painless or painful?
Typically seen around the knee or at the distal radius, but can also occur in other long bones, the pelvis and the spine
These tumours are locally destructive and destroy the cortex, and so are painful and may result in pathological fracture

What is the classical descriptive sign of a Giant Cell Tumour on Xray?
What genetic mutation are they associated with?
“Soap bubble” appearance on Xray
Characterised by a consistent translocation between chromosomes 1 and 2
What is Fibrous Dysplasia and where does it most commonly occur?
What is the classical radiological “buzzword”?
Disease of bone usually occuring in adolescence, genetic mutations result in lesions of fibrous bone tissue and immature bone
Can affect any bone, but most commonly affects bones of the head and neck
Classical radiological sign is “Shepherd’s Crook Deformity” if involving the head of the femur

Where do osteoid osteomas typically occur?
What is the classical radiological buzzword?
Small area of immature bone is surrounded by a “sclerotic halo”
Most commonly occur in adolescence with common sites being the head of the femur, diaphysis of long bones and vertebrae

Osteoid osteoma - clinical presentation
Typically adolescence
Intense, constant pain. Worse at night
What age group are primary malignant bone tumours more commonly seen in?
What are they commonly misdiagnosed as?
More common in younger age groups
Often misdiagnosed as muscular pain
What is the most common type of primary malignant bone tumour?
What gene is suppressed?
Osteosarcoma
Majority are associated with suppression of Retinoblastoma gene (tumour suppressor gene), causing uncontrolled production of bone
Where do osteosarcomas most commonly present?
What has happened in 10% of patients by the time of presentation?
Like osteochondromas, most common site of presentation is around the knee
By the time they present, 10% of patients already have lung mets
How do osteosarcomas and chondrosarcomas differ?
Chondrosarcomas are cartilage-producing, rather than bone producing
Chondrosarcomas tend to appear in older patients
While osteosarcomas typically present around the knee, chondrosarcomas are more often found in the pelvis and proximal femur
Chondrosarcomas are also less common than osteosarcomas
What age group does Ewing’s Sarcoma typically occur in and where does it commonly affect?
Again, like osteosarcomas, Ewing’s Sarcoma typically affects younger patients
May be associated with fever, raised inflammatory markers and a warm swelling
Tends to occur in long bones, especially the femur
What is the classical radiological buzzword associated with Ewing’s sarcoma?
What is the gene defect involved?
Buzzword - “onion-skin appearance”
Gene defect - majority are associated with a translocation involving the Ewing’s Sarcoma Gene (EWS) on chromosome 22 with chromosome 11 - t11:22

What other types of cancers might spread to bone?
Breast
Prostate
Lung
Renal
Thyroid
Questions you would ask about a soft-tissue swelling/growth
How long?
Painful?
Change in size?
More than one?
Potential causes of local soft-tissue swellings
Inflammatory - bursitis, rheumatoid nodules
Infection - abscess
Cystic lesions - ganglions, meniscal cyst, Baker’s Cyst
Where might malignant soft tissue swellings occur?
Angiosarcoma
Fibrosarcoma
Liposarcoma
Rhabdomyosarcoma
Synovial sarcoma
Where does bursitis commonly present?
What might cause it?
Pre-patellar
Olecranon (elbow)
Bunions
Caused by repeated pressure/trauma, bacterial infection or gout

What is a sebaceous cyst?
What happens when they rupture?
Extremely common soft-tissue swelling occuring in subcutaneous tissue
Painless and may slowly increase in size
Often excised in primary care
Once ruptured, they leak a cheesy substance made of degenerated keratin
What is important to remember when treating abscesses?
Antibiotics don’t penetrate them! Need to drain the abscess first to clear pus