Primary bone tumours Flashcards
What are the benign bone tumours?
Osteochondroma Osteoma Osteoid osteoma Osteoblastoma Chondroma Giant cell tumour
What is the most common benign tumour?
osteochondroma
Where does the tumour occur in osteochondroma?
metaphysis of long bones
Characteristics of osteochondroma?
growths laterally out of growth plate and is covered by cartilaginous cap
Where does an osteoma occur?
surface of facial bones
What is osteoma associated wtih?
gardner syndrome
Where does osteoid osteoma occur?
cortex of long bones
which cell causes the tumour in osteoid osteoma?
osteoblasts
presentation of osteoid osteoma?
Presents as bone pain that is worse at night and relieved the NSAIDS
Mass will be <2cm with radiolucent osteoid core
Where does an osteoblastoma occur?
vertebra
presentation of osteoblastoma?
bone pain that is worse at night but does not respond to NSAIDs
>2cm
Where does a chrondroma occur?
medulla of small bones in hands and feet
what is a chondroma?
a benign tumour of cartilage
Where does a giant cell tumour occur?
in the epiphysis of long bones (often knee)
appearance of giant cell tumour on xray?
soap bubble
pathophys of giant cell tumour?
mononuclear cells express RANKL and reactivate multinucleated giant cells (osteoclast like)
What are the primary metastatic bone tumours?
osteosarcoma
Chondrosarcoma
Ewing sarcoma
Is osteosarcoma more common in the young or old?
Young (males)
where does osteosarcoma occur?
Metaphysis of long bones (often in knee region)
Osteosarcoma histology
Pleomorphic osteoid-producing cells (malignant osteoblasts)
Osteosarcoma xray findings
codman triangle and sunburst pattern on xray
osteosarcoma presentation
painful enlarging mass
Location of chondrosarcoma
Medulla of pelvis, proximal femur and humerus
What is a chondrosarcoma?
tumour of malignant chondrocytes
Who most commonly gets ewing sarcoma?
Caucasian boys under 15
Where does ewing sarcoma occur?
Diaphysis of long bones (femur), pelvic flat bones
ewing sarcoma histology?
anaplastic smallblue cells (resemble lymphocytes)
Which fusion protein is present in ewing sarcoma?
t(11:22) - EWS-FLII
What will you see on xray of Ewing sarcoma?
onion skin periosteal reaction in bone