Bone Tumours

Question 1

What is an osteoma and where does it most commonly occur?

Answer 1

A benign overgrowth of bone most commonly occurring on the skull.

Question 2

Which hereditary condition is associated with osteomas?

Answer 2

Gardner’s syndrome (a variant of familial adenomatous polyposis, FAP).

Question 3

What is the most common benign bone tumour?

Answer 3

Osteochondroma (exostosis).

Question 4

What is the typical demographic for osteochondroma?

Answer 4

Males under 20 years old.

Question 5

What is the characteristic anatomical appearance of an osteochondroma?

Answer 5

A cartilage-capped bony projection on the external bone surface.

Question 6

Which tumour consists of multinucleated giant cells in a fibrous stroma?

Answer 6

Giant cell tumour.

Question 7

What is the peak incidence age for giant cell tumour?

Answer 7

20–40 years.

Question 8

Where do giant cell tumours most commonly occur?

Answer 8

Epiphyses of long bones.

Question 9

What is the classic X-ray appearance of a giant cell tumour?

Answer 9

“Double bubble” or “soap bubble” appearance.

Question 10

What is the most common primary malignant bone tumour?

Answer 10

Osteosarcoma.

Question 11

Which age group is most commonly affected by osteosarcoma?

Answer 11

Children and adolescents.

Question 12

Where does osteosarcoma most frequently arise?

Answer 12

Metaphyseal region of long bones before epiphyseal closure (40% femur, 20% tibia, 10% humerus).

Question 13

What X-ray features are characteristic of osteosarcoma?

Answer 13

Codman triangle (periosteal elevation) and “sunburst” pattern.

Question 14

Which genetic mutation significantly increases the risk of osteosarcoma?

Answer 14

Rb gene mutation (associated with retinoblastoma).

Question 15

Which conditions predispose to osteosarcoma?

Answer 15

Paget’s disease of bone and prior radiotherapy.

Question 16

What type of tumour is Ewing’s sarcoma histologically?

Answer 16

Small round blue cell tumour.

Question 17

Which age group is primarily affected by Ewing’s sarcoma?

Answer 17

Children and adolescents.

Question 18

Which sites are most commonly affected by Ewing’s sarcoma?

Answer 18

Pelvis and long bones.

Question 19

What genetic translocation is associated with Ewing’s sarcoma?

Answer 19

t(11;22) resulting in the EWS-FLI1 fusion gene.

Question 20

What is the typical X-ray appearance of Ewing’s sarcoma?

Answer 20

“Onion skin” periosteal reaction.

Question 21

What type of tissue gives rise to chondrosarcoma?

Answer 21

Malignant cartilage.

Question 22

Which part of the skeleton is most commonly affected by chondrosarcoma?

Answer 22

Axial skeleton.

Question 23

Which age group is most commonly affected by chondrosarcoma?

Answer 23

Middle-aged adults.