HISTO: Bone tumours

Question 1

List 3 benign bone forming tumours.

Answer 1

Osteoid osteoma
Osteoblastoma
Osteoma

Question 2

List 3 benign cartilaginous differentiation tumours.

Answer 2

Osteochondroma - pedunculated
Enchondroma - hands/feet
Chondroblastoma

Question 3

Which syndrome is associated with fibrous dysplasia?

Answer 3

McCune Albright - cafe au lait and endocrine problems and fibrous dysplasia

Question 4

What mutation is seen in fibrous dysplasia?

Answer 4

GNAS

Question 5

What is “soap bubble osteolysis” a feature of?

Answer 5

Fibrous dysplasia

Question 6

What is “chinese letters” bone biopsy associated with?

Answer 6

Fibrous dysplasia - rounded and curved trabeular bone and marrow replaced by fibrous stroma

Question 7

What is “shepherd’s crook deformity” characteristic of?

Answer 7

Fibrous dysplasia

Question 8

How do osteochondromas present?

Answer 8

Pedunculated - have a cartilaginous surface, mimic tubular bone

Question 9

What is “popcorn calcification” characteristic of?

Answer 9

Enchondroma

Question 10

Where do giant cell tumours usually occur?

Answer 10

Epiphyses but extend to metaphysis, mostly females

Question 11

Where do chondroblastomas usually occur?

Answer 11

Ends of long bones

Question 12

What are “lytic lesions, with osteoclasts on background of spindle/ovoid cells” characteristic of?

Answer 12

Giant cell tumour

Question 13

Which benign bone tumour can be locally aggressive?

Answer 13

Giant cell tumour (borderline malignant)

Question 14

What are the “giant” cells in giant cell tumours?

Answer 14

Osteoclasts

Question 15

What are 3 primary malignant bone tumours?

Answer 15

Osteosarcoma
Chondrosarcoma
Ewin’s/PTEN

Question 16

What is “Codman’s triangle” characteristic of?

Answer 16

Osteosarcoma

Question 17

Which tumour is made of malignant mesenchymal cells +/- bone/cartilage?

Answer 17

Osteosarcoma

Question 18

What is the red cytoplasm of osteosarcoma cells positive for?

Answer 18

ALP

Question 19

Compare the prognosis of the primary malignant bone tumours.

Answer 19

Osteosarcoma - 60% 5yr survival - adolescent
Chondrosarcoma - 70% 5yr survival - adult >40yrs
Ewing’s - 75% 5y survival - adolescents

Question 20

Which malignant bone tumour usually affects the proximal skeleton?

Answer 20

Chondrosarcoma

Question 21

What tumour has XR of bone that is “lytic with fluffy calcification”?

Answer 21

Chondrosarcoma

Question 22

What type of cells are seen in Ewing’s?

Answer 22

Small round cell tumour

Question 23

What tumour has XR of bone that shows “onion skinning of the periosteum”?

Answer 23

Ewing’s

Question 24

What mutation is seen in Ewing’s?

Answer 24

11:22 (EWS/Fli1)

Question 25

What is characteristic of Ewing’s on immunostaning?

Answer 25

Synaptophysin and S100 may be positive (these are also positive in neuroblastomas)
CD99

Question 26

Name 3 soft tissue tumours.

Answer 26

Liposarcoma/myxoid
Pleiomorphic
Spindle cell tumour

Question 27

Why are synovial sarcomas “biphasic” tumours?

Answer 27

They have epithelial and spindle cell areas

Question 28

What are the good prognostic factors for a soft tissue tumour?

Answer 28

<5cm, superficial to deep fascia, diploid, low proliferation and tumour suppressor gene present

Question 29

Which tumours are poorly vascularised and so bad for chemotherapy?

Answer 29

Osteosarcoma

Question 30

What are giant cell granulomas also known as?

Answer 30

Reparative tumours

Question 31

What is the most common type of bone tumour overall?

Answer 31

Metastatic