Pathology - Benign Bone tumours

Question 1

The most common benign bone tumour is a(n) _________

Answer 1

Osteochondroma

Question 2

Osteochondroma produces a ______________ with a ___________

Answer 2

Osteochondroma produces a bony outgrowth on the external surface with a cartilaginous cap

Question 3

Osteochondroma does not usually cause any problems or pains - true/false

Answer 3

False - it doesn’t usually cause any problems except for local pains

Question 4

What is the risk of an osteochondroma undergoing malignant transformation?

Answer 4

1%

Question 5

Multiple osteochondromata can occur as part of an autosomal/x-linked dominant/recessive hereditary disorder.

Answer 5

Multiple osteochondromata can occur as part of an autosomal dominant hereditary disorder

Question 6

Enchondroma is intra/extramedullary

Answer 6

Enchondroma is intramedullary

Question 7

An enchondroma is usually located in the diaphysis/epiphysis/metaphysis - it is ____________

Answer 7

An enchondroma is usually located in the metaphysis - it is metaphyseal

Question 8

An enchondroma is an osseous tumour - true/false

Answer 8

false - it is cartilaginous

Question 9

Enchondromas are caused by what?

Answer 9

A failure of enchondral ossification at the growth plate

Question 10

An enchondroma is usually radiopaque - true/false

Answer 10

false - usually radiolucent but may have a patchy sclerotic appearance

Question 11

Enchondromas are usually _________ findings and thus are usually ___________

Answer 11

Enchondromas are usually incidental findings and so are usually asymptomatic

Question 12

While many enchondromas are asymptomatic, what can they cause?

Answer 12

They can cause pathological fractures

Question 13

List the 5 places where an enchondroma may occur

Answer 13

small bones of foot, tibia, femur, humerus and small bones of hands.

Question 14

When might you treat an enchondroma (give two times) and how would you treat it?

Answer 14

When a pathological fracture has already occurred and healed
When there is a risk of impending fracture
Curettage and then fill in with bone graft to strengthen the bone.

Question 15

What is a simple bone cyst?

Answer 15

A simple bone cyst is a single chamber fluid filled cyst in a bone.

Question 16

What causes a simple bone cyst?

Answer 16

A growth defect in the physis

Question 17

Where may a simple bone cyst occur? Is it diaphyseal, metaphyseal or epiphyseal?

Answer 17

Usually in the femur or humerus or talus and calcaneus.

Usually metaphyseal in long bones or physeal.

Question 18

Are simple bone cysts usually symptomatic?

Answer 18

No - they are usually incidental findings in children and young adults.

Question 19

What symptomatic problem may a simple bone cyst cause?

Answer 19

Pathological fractures

Question 20

What is the treatment for a simple bone cyst?

Answer 20

Same as for an enchondroma - curettage, bone grafting, with or without stabilisation.

Question 21

What is an aneurysmal bone cyst?

Answer 21

A multi-chamber blood or serum filled cyst of a bone

Question 22

Are the multiple chambers of an aneurysmal bone cyst seen on xray?

Answer 22

Yes

Question 23

It is believed that aneurysmal bone cysts are caused by________________

Answer 23

a small AVM

Question 24

Aneurysmal bone cysts can occur where?

Answer 24

In the metaphysis of many different long bones
flat bones (e.g. the ribs and skull)
Vertebral bodies

Question 25

Are aneurysmal bone cysts usually symptomatic? Are they locally invasive or aggressive?

Answer 25

yes - they usually cause pain. yes they are locally aggressive and cause cortical destruction.

Question 26

Can aneurysmal bone cysts cause pathological fractures?

Answer 26

Yes

Question 27

How are aneurysmal bone cysts treated?

Answer 27

They are usually treated with curettage and bone grafting or the use of bone cement.

Question 28

Name this tumour: Locally invasive tumour that is most commonly in the metaphyseal region but can involve the epiphysis and move to the subchondral region near a joint

Answer 28

Giant cell tumour

Question 29

Where is the most common site(s) for a giant cell bone tumour

Answer 29

most commonly around the knee and distal radius

Question 30

List all other places, besides the knee and distal radius, that a GCT can occur.

Answer 30

other long bones
Pelvis
Spine

Question 31

Giant cell tumours are locally aggressive and destroy ___________

Answer 31

Cortical bone

Question 32

Giant cell tumours do not cause pain - true/false

Answer 32

False - they can be very painful

Question 33

Giant cell tumours cannot cause pathological fracture - true/false

Answer 33

False - they can cause pathological fracture.

Question 34

Histology shows that giant cell tumours are made up of mono-nucleate/multinucleate giant cells

Answer 34

Multi-nucleate giant cells.

Question 35

Give a description of a giant cell tumour as seen on x-ray

Answer 35

Soap bubble appearance

Question 36

Normally considered benign, what percentage of giant cell bone tumours can metastasise to the lung to form a benign GC lung tumour?

Answer 36

5%

Question 37

What is treatment of giant cell bone tumours?

Answer 37

Intralesional incision with phenol, bone cement or liquid nitrogen to destroy any remaining tumour and reduce recurrence.

Question 38

Very severe local cortical destruction with a giant cell tumour may need joint replacement - true/false

Answer 38

true

Question 39

Fibrous dysplasia is __________________________

Answer 39

A disease of bone usually occurring in adolescence which is a genetic mutation resulting in the formation of fibrous tissue and immature bones

Question 40

Fibrous dysplasia can be monostotic or polyostotic - define these terms

Answer 40

affecting one bone (mono) or more than one bone (poly)

Question 41

What causes angular deformity in fibrous dysplasia?

Answer 41

Defective mineralisation

Question 42

The affected bone(s) in fibrous dysplasia are wider/narrower with thickened/thinned cortices

Answer 42

The affected bones in fibrous dysplasia are wider with thickened cortices.

Question 43

Which occurs in fibrous dysplasia - pathological or stress fractures?

Answer 43

Stress fractures

Question 44

Name the deformity caused by extensive involvement of the proximal femur in fibrous dysplasia

Answer 44

Shepherds crook deformity

Question 45

Simple intralesional excision for fibrous dysplasia has a very high/low rate of recurrence

Answer 45

Simple intralesional excision of fibrous dysplasia has a very high rate of recurrence.