Pathology: Benign Bone Tumours

Question 1

how do a lot of bone tumours present

Answer 1

non specifically:

• pain
• soft tissue mass
• compression of adjacent structures
• acutely with fracture

Question 2

osteochondroma

Answer 2

common bony outgrowth on the external surface of bone that is covered in cartilaginous cap

Question 3

location of osteochondroma

Answer 3

typically around epiphysis of long bones - most commonly knee

Question 4

treatment of osteochondroma

Answer 4

if are growing or causing pain excise as they have a small risk of malignancy

Question 5

CF of osteochondroma

Answer 5

do not usually cause problems but can cause localised pain

Question 6

what are multiple osteochondromas associated with

Answer 6

genetic disorders

Question 7

enchondroma

Answer 7

intramedullary cartilaginous tumour - cartilage that lines the inside of the bones

Question 8

what is the appearance of enchondroma

Answer 8

usually lucent but can undergo mineralisation to become PATCHY SCLEROTIC appearance

Question 9

what can an enchondroma result in

Answer 9

weakens bone - fracture

Question 10

where do enchondroma usually occur

Answer 10

classically small tubular bones of hands and feet usually metaphyseal

Question 11

treatment of enchondroma

Answer 11

benign - simply scrape off bone

Question 12

simple bone cyst

Answer 12

solitary unicystic fluid filled neoplasm

Question 13

location of simple bone cysts

Answer 13

metaphyseal long bones (humerus and femur), and also talus and calcaneus

Question 14

CF of simple bone cyst

Answer 14

asymptomatic and therefore an incidental finding on Xray can cause weakness leading to fracture

Question 15

treatment of simple bone cyst

Answer 15

curettage and bone grafting

Question 16

aneurysmal bone cyst

Answer 16

lots of chambers filled with blood or serum

Question 17

what are aneurysmal bone cyst due to

Answer 17

arteriovenous malformation

Question 18

location of aneurysmal bone cyst

Answer 18

metaphyses of many different bones

Question 19

features of aneurysmal bone cyst

Answer 19

expansile lesion usually locally aggressive and causes cortical expansion and destruction - painful risk of fracture

Question 20

treatment of aneurysmal bone cyst

Answer 20

curettage and grafting or use of bone cement

Question 21

giant cell tumours

Answer 21

many multi nucleated giant cells

Question 22

what are the giant cells characterised by

Answer 22

consistent translocation between chromosome 1 and 2

Question 23

where in the bone are giant cell tumours found

Answer 23

metaphyseal and epiphyseal region can extend to subchondral bone adjacent to joint

Question 24

GCT common sites

Answer 24

knee and distal radius

Question 25

characteristics of GCT

Answer 25

benign but locally aggressive

can metastasise to lungs with benign pulmonary GCT. these have an excellent prognosis

Question 26

CF of GCT

Answer 26

cause pain and can cause fracture

Question 27

what is seen onX ray wtih GCT

Answer 27

soap bubble appearance

Question 28

treament of GCT

Answer 28

intralesional excision with use of phenol, bone cement or liquid nitrogen to destroy tumour material and reduce risk of occurrence

there is a small malignant risk

Question 29

how do you treat very aggressive GCT lesions with cortical destruction

Answer 29

joint replacement

Question 30

fibrous dysplasia

Answer 30

disease of bone occurring in adolescence where a genetic mutation results in lesions of fibrous tissue develops instead of normal bone and causes immature bone

weakens bone predisposing to fracture

can be monostotic or polystotic

Question 31

common locations of fibrous dysplasia

Answer 31

head and neck are frequent

Question 32

aetiology of fibrous dysplasia

Answer 32

usually a mutation causing abnormality in G protein signalling

Question 33

what do patients with polystotic fibrous dysplasia often have

Answer 33

endocrine disorders (G protein mutations)

Question 34

which genetic condition is fibrous dysplasia associated with

Answer 34

• McCune Albright
• polystotic fibrous dysplasia
• also see café au lait macules, hormonal abnormalitites etc

Question 35

features of fibrous dysplasia

Answer 35

defective mineralisation results in angular deformities and the affected bone is wider with thinned cortices

stress fractures can occur

Question 36

what happens when the proximal femur is involved in fibrous dysplasia

Answer 36

sheperds crook deformity

Question 37

what is used to reduce pain in fibrous dysplasia

Answer 37

biphosphonate

Question 38

treatment of fibrous dysplasia caused fractures

Answer 38

stabilised with internal fixation and cortical bone grafts

Question 39

osteoid osteoma

Answer 39

small nidus of immature bone surrounded by sclerotic halo

Question 40

when do osteoid osteoma most commonly occur

Answer 40

adolescence

Question 41

where do osteoid osteoma most commonly occur

Answer 41

long bones

Question 42

CF of osteoid osteoma

Answer 42

persistent pain that is worse at night and relieved by NSAIDs

Question 43

diagnosis of osteoid osteoma

Answer 43

may be seen on X ray bone scan and CT scan can confirm diagnosis

Question 44

treatment of osteoid osteoma

Answer 44

may resolve spontaneously CT guided radiofrequency ablation

Question 45

what can also present with a lytic lesion of bone

Answer 45

brodies abscess (osteomyelitis) and hyperparathyroidism (Browns tumours)

Question 46

A mostly lucent lesion, with a patchy sclerosis, found within the metaphyseal region of short tubular bones.

Answer 46

enchondroma

Question 47

A lucent, multi-loculated cyst found within the medulla of many different bones, often with associated cortical expansion.

Answer 47

aneurysmal bone cyst

Question 48

A bony spur, originating the in metaphyseal regions of long bones, growing away from the epiphysis.

Answer 48

osteochondroma