Benign bone-cartilage tumours

Question 1

Define primary bone tumour?

Answer 1

Neoplasm/new growth that originates in bone

Question 2

Are primary bone tumours common compared to secondary bone tumours?

Answer 2

No, primary bone tumours are uncommon

Question 3

Do primary bone tumours tend to affect all age groups?

Answer 3

No, tend to affect certain age groups and locations

Question 4

What are the 2 ways in which bone tumours are classified?

Answer 4

What normal cell type they originate from

What matrix they produce

Question 5

In which age range are benign tumours most likely to occur?

Answer 5

First 3 decades of life (0-30)

Question 6

Are benign or malignant tumours more common in general?

Answer 6

Benign tumours are more common than malignant tumours in general

Question 7

Are older adults more likely to be affected by benign or malignant tumours?

Answer 7

Malignant tumours

Question 8

What normal cell type does osteoma arise from?

Answer 8

Osteoblast

Question 9

What is the maturity of the bone that is predominantly affected by osteoma?

Answer 9

Predominantly affects mature bone

Question 10

Which body region is typically affected by osteoma, and give 3 specific areas within this region?

Answer 10

Cranio-facial region, especially jaw bones, temporal bones and paranasal sinuses

Question 11

Which syndrome is osteoma a feature of?

Answer 11

Gardner syndrome

Question 12

What are the 2 defining features of Gardner syndrome, and what kind of inheritance causes it?

Answer 12

Gardener syndrome is an autosomal dominant disorder that is characterised by multiple colorectal polyps (eg. inside large bowel) and tumours outside the colon

Question 13

Are tumours outside the colon always benign, in patients with Gardner syndrome?

Answer 13

No, they are different kinds of benign and malignant tumours

Question 14

Define polyp?

Answer 14

Projecting growth of tissue from a body surface, usually mucous membrane

Question 15

Which normal cell type gives rise to enchondroma, and which part of the bone does this arise from?

Answer 15

hyaline cartilage

arises within medullary cavity

Question 16

Do enchondromas commonly become malignant?

Answer 16

No, rarely become malignant

Question 17

What condition increases the risk of enchondromas becoming malignant tumours?

Answer 17

Enchondromatosis (multiple enchondromas)

Question 18

Which 2 conditions is enchondromatosis a characteristic feature of?

Answer 18

Ollier disease, Mafucci syndrome

Question 19

Which normal cell type gives rise to juxtacortical/periosteal chondroma, and which part of the bone does this arise from?

Answer 19

Hyaline cartilage

Arises from cortex

Question 20

Which part of the bone typically has tumour growth on the cortex, which have arisen from hyaline cartilage, and what is the classification of this tumour?

Answer 20

Juxtacortical/periosteal chondroma

Tumours arise on cortex on metaphysis of long tubular bones (eg. humerus, femur) or small tubular bones (eg. phalanges in hands and feet)

Question 21

What are the 3 x-ray features of juxtacortical/periostral chondroma?

Answer 21

Circumscribed (confined to one area) lucency with central irregular calcifications

Sclerotic rim

Intact cortex

Question 22

What is the characteristic shape of osteochondroma?

Answer 22

Exostosis (cartilage-capped tumour)

Question 23

Which region of the bone does osteochondroma typically grow from, and what structure grows to connect to this area?

Answer 23

Metaphysis of long tubular bones (near growth plate)

Question 24

Are bones affected by osteochondroma typically formed by endochondral or intramembranous ossification?

Answer 24

Endochondral ossification

Question 25

Is osteochondroma more likely in men or women?

Answer 25

3x more likely in men

Question 26

Is osteochondroma fast or slow growing?

Answer 26

Slow growing

Question 27

Give 2 ways in which osteochondroma becomes painful?

Answer 27

Infringes on nerve Bony stalk is fractured

Question 28

In most patients, are osteochondromas solitary or multiple?

Answer 28

Solitary

Question 29

What age range is typically affected by solitary osteochondromas?

Answer 29

Late adolescence/early adulthood

Question 30

What condition is multiple osteochondromas a feature of?

Answer 30

multiple hereditary exostosis syndrome

Question 31

Why is multiple hereditary exostosis syndrome commonly diagnosed in childhood?

Answer 31

Underlying bone bowed and shortened due to disrupted longitudinal growth from growth plate which has resulted in multiple osteochondromas

Question 32

What is the difference between a sessile and pedunculated osteochondroma?

Answer 32

Osteochondromas with a visible stalk are called pedunculated. Flatter ones with a broader base are called sessile

Question 33

What direction does pedunculated osteochondroma typically point in relative to the joint?

Answer 33

Points away from the joint

Question 34

Does the parent bone grow continuously with the pedunculated osteochondroma?

Answer 34

Yes, medullary cavity and cortex grow continuously

Question 35

How thick is the cartilage cap of an osteochondroma?

Answer 35

2-3mm thick

Question 36

What unusual radiological feature could be caused by a secondary pedunculated osteochondroma?

Answer 36

cartilage cap of lesion in excessively thick/irregular

Question 37

How does the bony stalk of the pedunculated osteochondroma grow continuously with the parent bone?

Answer 37

Lesion undergoes endochondral ossification and trabecular bone fuses with normal trabecular bone below

Question 38

Which bones are commonly affected by osteoid osteoma?

Answer 38

Osteoblast tumour that usually arise in cortex of long bones (mostly femur, tibia and lower extremities)

Question 39

What is usually the diameter of osteoid osteoma?

Answer 39

Less than 2 cm

Question 40

What is the usual age range of patients with osteoid osteoma, and are they more common in men or women?

Answer 40

Occurs in adults under 25 and is more common in men than women

Question 41

What is the characteristic radiological feature of osteoid osteoma?

Answer 41

Thick rim of reactive cortical bone with radiolucent core

Question 42

What is the characteristic macroscopic feature of osteoid osteoma?

Answer 42

Rounded, oval mass of red-brown tissue located on the cortex

Question 43

What is the characteristic microscopic feature of osteoid osteoma?

Answer 43

Radiolucent nidus containing trabecular bone, cancer cells and vascular tissue surrounded by sclerotic bony shell

Question 44

How intense is the pain caused by osteoid osteoma, and is it constant throughout the day?

Answer 44

Severe pain at night

Question 45

What substance is released by osteoblasts that causes pain, in a patient with osteoid osteoma, and what drug class is prescribed for pain relief?

Answer 45

Pain caused by prostaglandins released by osteoblasts Relieved by NSAIDs

Question 46

What normal cell type does osteoblastoma originate from, and which body region is most commonly affected?

Answer 46

Osteoblast tumour Predominantly affects posterior components of vertebrae, long bones of lower limbs

Question 47

Do osteoblastomas usually become malignant?

Answer 47

Rarely become malignant

Question 48

How can you differentiate between osteoid osteoma and osteoblastoma in terms of size?

Answer 48

Osteoid osteoma are less than 2cm in diameter Osteoblastoma are more than 2cm in diameter

Question 49

What kind of pain does a patient with osteoblastoma usually present with?

Answer 49

Vertebral pain with no marked bony reaction Isn't relieved by aspirin

Question 50

Which 2 normal cell types give rise to Giant Cell Tumour of bone?

Answer 50

Multinucleated giant stromal cells (osteoclast precursors) Osteoclasts

Question 51

Which part of the bone is typically affected by Giant Cell Tumour of bone, and give 2 specific examples of long bones?

Answer 51

Epiphysis of long bones Distal femur, proximal tibia (any long bones near joint)

Question 52

Why does a patient with Giant Cell Tumour of bone present with arthritic symptoms?

Answer 52

Tumour is near joint

Question 53

Does Giant Cell Tumour of bone affect all ages equally?

Answer 53

No, almost exclusively in young adults

Question 54

Does Giant Cell Tumour of bone commonly metastasise to lungs, and is this always fatal?

Answer 54

4% metastasise to lungs, but these can spontaneously regress so are rarely fatal

Question 55

What is the characteristic radiological feature of Giant Cell Tumour of bone, and why does this occur?

Answer 55

Expansive lytic lesion with 'soap bubble' appearance Neoplastic osteoclast precursors express high RANKL levels, so osteoclast proliferation and bone resorption occurs at fast rate, produces lytic lesions

Question 56

Explain how Giant Cell Tumour of bone is treated with cutterage?

Answer 56

Curette instrument is used to scrape the tumour out of the bone, then cavity is filled with a bone graft 40-60% treated tumours recur locally