Bone tumours

Question 1

What is an osteoma, and with which condition is it associated?

Answer 1

Benign overgrowth of bone, most commonly occurring on the skull

= It is associated with Gardner’s syndrome, a variant of familial adenomatous polyposis (FAP)

Question 2

What is the most common benign bone tumour and describe it

Answer 2

Osteochondroma

(1) Tumour arises from a growth plate
(2) Produces a bony outgrowth on the external surface with a cartilaginous cap
(3) Painless, hard lump

Question 3

In which age group is osteochondroma most commonly diagnosed?

Answer 3

under 20 years

Question 4

What is giant cell tumour?

Answer 4

Benign tumour arising from the giant cells of the bone marrow

(1) Painful mass/swelling
(2) Commonly occur around the knee and in the distal radius
(3) Consist of multi-nucleated giant cells

Question 5

What is a characteristic X-ray finding for a giant cell tumour?

Answer 5

‘double bubble’ or ‘soap bubble’ appearance

Question 6

What is the peak incidence age range for a giant cell tumour?

Answer 6

The peak incidence for a giant cell tumour is between 20-40 years

Question 7

What tumour shows a shepherd’s crook’ deformity on an X-Ray and how does that come about?

Answer 7

Benign Fibrous Dysplasia

= Extensive involvement of the proximal femur

Question 8

Describe a Osteoid Osteoma

Answer 8

(1) benign
(2) occurs in long bones in children
(3) Intense constant pain, worse at night
(4) NSAIDs help
(5) Small nidus of immature (woven) bone surrounded by an intense sclerotic halo is seen in CT scan

Question 9

Which bone tumour is the most common primary malignant bone tumour?

Answer 9

Osteosarcoma is the most common primary malignant bone tumour, especially in children and adolescents

Question 10

What is a characteristic X-ray finding in osteosarcoma?

Answer 10

Codman triangle (periosteal elevation) and a ‘sunburst’ pattern

Question 11

Which genetic mutation significantly increases the risk of osteosarcoma?

Answer 11

Mutation of the Rb gene significantly increases the risk of osteosarcoma

Question 12

What is a common predisposing factor for osteosarcoma?

Answer 12

Paget’s disease of the bone and radiotherapy

Question 13

What is the most common location for Ewing’s sarcoma?

Also describe thsi tumour

Answer 13

pelvis and long bones

= (1) 2nd most typical malignant bone tumour in children
(2) Hot, swollen, tender joint or limb with raised inflammatory markers - can mimic infection
(3) small round blue cell tumour

Question 14

What is the genetic abnormality associated with Ewing’s sarcoma?

Answer 14

t(11;22) translocation

Question 15

What is a characteristic X-ray finding in Ewing’s sarcoma?

Answer 15

‘onion skin’ appearance

Question 16

What type of tumour is chondrosarcoma, and where is it most commonly located?

Answer 16

Chondrosarcoma is a malignant tumour of cartilage and is most commonly located in the axial skeleton
= pelvis or proximal femur

(1) malignancy of chondrocytes

Question 17

At what age is chondrosarcoma most commonly diagnosed?

Answer 17

Middle-aged individuals

Question 18

The most common benign soft tissue tumour is what?

Answer 18

Lipomas

Question 19

The most common tumour-causing bone metastases (in descending order) are what?

Answer 19

1. Prostate
2. Breast
3. Lung

Question 20

The most common site (in descending order) for bone metastases is what?

Answer 20

1. spine
2. pelvis
3. ribs
4. skull
5. long bones

Question 21

What are the bone metastases features?

Answer 21

(1) pathological fractures
(2) hypercalcaemia
(3) raised ALP
(4) Bone pain

Question 22

An 80-year-old man presents to the emergency department with back pain. He has no documented past medical history. An x-ray spine shows vertebral wedge compression fractures and focal sclerotic bony lesions.

What is the most likely diagnosis?

Answer 22

Metastatic prostate/ lung/ breast cancer

Question 23

A 13-year-old boy presents to his general practitioner with a 3-month history of a growing lump on the posterior aspect of his right arm, which has become extremely painful over the last two weeks. A shoulder radiograph is ordered, which identifies a lytic lesion in the diaphysis of the right humerus with an ‘onion skin’ appearance.

What is the most likely diagnosis?

Answer 23

Ewing’s sarcoma

Question 24

A 12-year-old girl presents to her general practitioner with a 4-month history of a dull, aching pain and swelling in the distal aspect of her right thigh. She is otherwise well and has a family history of retinoblastoma.

A knee radiograph identifies a triangular area of new subperiosteal bone in the metaphyseal region of the femur, with a ‘sunburst’ pattern.

What is the most likely diagnosis?

Answer 24

Osteosarcoma

Question 25

A 52-year-old male presents to the GP clinic with a three-month history of pain in his pelvis which has been worsening. The pain is worse on the right and at night; he describes it as a dull ache. He does not have any recent trauma to the region On examination, there is tenderness over the lateral side of his right pelvis. An x-ray of his pelvis reveals a poorly defined 4cm bone lesion in the right ilium with a moth-eaten pattern of bone destruction What is the most likely diagnosis?

Answer 25

Chondrosarcoma

Question 26

What bone tumour shows this on an X-ray? 'moth-eaten pattern of bone destruction'

Answer 26

Chondrosarcoma