Histopathology 2 - Bone tumours Flashcards

1
Q

What is the preferred investigation for diagnosing bone tumours?

A

Core biopsy under radiological guidance

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2
Q

What is “shepherd’s crook deformity” a reference to?

A

Fibrous dysplasia involving the femoral head

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3
Q

Recall 4 tumour-like conditions of the bone that are not actually malignant

A
  1. Fibrous dysplasia
  2. Fibroma (can be ossifying/ non-ossifying)
  3. Reparative giant cell granuloma
  4. Simple bone cyst
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4
Q

How does osteochondroma mimic bone in appearance?

A

They have a cartilaginous surface overlying normal cortical + trabecular bone

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5
Q

In which bones is osteochondroma most likely to present?

A

Long bones

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6
Q

How will enchondroma appear on XR?

Which bones are affected?

A

“popcorn” pattern

usually affects the fingers/hands

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7
Q

Is a giant cell tumour of bone benign or malignant?

A

Borderline malignant

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8
Q

What is the typical age of presentation of osteochondroma?

A

20-40 years

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9
Q

What is the typical age of presentation of giant cell tumour of bone?

A

20-40 years

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10
Q

How do giant cell bone tumours appear under the microscope?

A

Osteoclasts on a background of ovoid cells

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11
Q

What are the 3 types of malignant bone tumour?

A

Osteosarcoma (bone-forming)
Chondrosarcoma (cartilage-forming)
Ewing’s sarcoma (undifferentiated mesenchymal)

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12
Q

Recall the typical age of presentation for each of the 3 types of malignant bone tumour

A

Osteosarcoma: <30 years
Chondrosarcoma: >40 years
Ewing’s sarcoma: <20 years

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13
Q

Recall the typical site affected for each of the 3 types of malignant bone tumour

A

Osteosarcoma: knee
Chondrosarcoma: pelvis/ proximal skeleton
Ewing’s sarcoma: long bones + pelvis

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14
Q

Recall the typical X ray appearance of each of the 3 types of malignant bone tumour

A

Osteosarcoma: Codman’s triangle
Chondrosarcoma: fluffy calcification
Ewing’s sarcoma: Onion-skinning of periosteum

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15
Q

What is a “Codman’s triangle”?

A

The triangular area of new subperiosteal bone that is created when a lesion, often a tumour, raises the periosteum away from the bone.

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16
Q

Which of the 3 types of malignant bone tumour has the best prognosis?

A

Chondrosarcoma

*the adult one**

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17
Q

What gene mutation is associated with Ewing’s sarcoma?

A

11:22 translocation

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18
Q

Which type of malignant bone tumour will stain for CD99 and MICC2?

A

Ewing’s sarcoma

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19
Q

Which patients are most at risk of developing Ewing’s tumour in soft tissue?

A

Immunocompromised patients

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20
Q

What are the 5 metabolic bone diseases

A

Osteoporosis

Osteomalacia/rickets

Hyperparathyoridism

Paget’s disease

Renal osteodystrophy

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21
Q

Compare the aetiology of the 5 metabolic bone diseases

A
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22
Q

DEXA score in osteoporosis

A

<2.5 SD: osteoporosis

1-2.5: osteopaenia

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23
Q

Osteoporisis vs osteomalacia: disease features

A

Osteoporisis: decreased bone mass

Osteomalacia: decreased bone mineralization

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24
Q

Disease features of paget’s disease

A

Lytic and sclerotic lesions

Phases:

a) lytic
b) mixed
c) osteosclerotic

**also causes deafness**

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25
Q

Types of fractures seen in osteoporosis

A

Neck of femur

Wrist - colle’s fractures

Vertebral fractures

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26
Q

Features of rickets/osteomalacia

A

Adults:

bone pain/tenderness, proximal muscle weakness

Children:

Rachitic rosary

Bowing of legs

Bone pain

frontal bossing

pigeon chest

delayed walking

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27
Q

Paget’s disease epidemiology

A

>50yo

M=F

28
Q

X-ray changes of osteoporiss

A

Usually none

29
Q

X-ray changes of rickets/osteomalacia

A
  • Looser’s zones fractures (pseudo-fractures)
  • splaying of metaphysis
  • Bowing of legs in rickets
30
Q

X-ray features of primary hyperparathyoridism i.e. osteitis fibrosa cystica

A
  • Brown’s tumours
  • Salt and pepper skull
  • sub-periosteal bone resoorption in phalanges
31
Q

X-ray changes in paget’s disease

A
  • mixed lytic and scleortic lesions
  • skull
    • osteoporisis circumscirpta
    • cotton wool
  • vertebrae
    • picture frame
    • ivory vertebra
  • pelvis
    • sclerosis and lucency
32
Q

Histology of osteoporisis

A

Loss of cancellous bone

33
Q

Histology of rickets

A

Excess unmineralized bone (osteoid)

34
Q

Histology of paget’s disease

A

huge osteoclasts

mosaic pattern of lamellar bone

35
Q

Biochemical features of the 5 metabolic bone diseases

A
36
Q

Gout vs pseudogout

A

Gout: caused by dietary factors

Pseudogout: metabolic conditions (hyperPTH, DM, hypothyroid)

37
Q

What organism causes osteomyelitis in

a) adults
b) children
c) sickle cell patients

A

Adults- Staph aureus

Children - h. influenzae, GBS

Sickle cell patients - salmonella

38
Q

X-ray changes of osteomyelitis

A

sub-periosteal new bone formation -early

lytic destruction of bone - 10 days

**opposite to paget’s where you get lytic first then sclerotic

39
Q

Hand changes of osteoarthirtis

A

Heberdeens and bouchard’s nodes

B: PIP

Heberdeens: DIP joint

40
Q

Osteoarthirtis x-ray features

A

LOSS

Loss of joint space

Osteophytes

Subchondral sclerosis

Subchondral cysts

41
Q

Which joint is spared in RA?

A

DIPJ

42
Q

Characteristic deformities of RA

A

Characteristic deformities:
● Radial deviation of wrist and ulnar deviation of fingers.
● “swan neck” and “Boutonniere” deformity of fingers
● Swan neck = hyperextension of PIPJ & flexion of DIPJ ● Boutonniere = flexion of PIPJ & hyperextension of DIPJ
● “Z” shaped thumb ● Synovial swelling
Extra-articular features: Pulmonary fibrosis, vasculitis, amyloidosis, pericarditis, subcutaneous
nodules, DVT

43
Q

Histopathology of RA

A

thickening of synovial membrane, hyperplasia of surface synoviocytes, intense
inflammatory cell infiltrate & fibrin deposition & necrosis

44
Q

X-ray changes of benign vs malignant bone diseases

A
45
Q

What are the malignant bone tumours?

A
  1. Osteosarcoma
  2. Chondrosarcoma
  3. Ewing’s sarcoma
  4. Giant cell (borderline malignancy)
46
Q

Osteosarcoma:

a) age
b) bones affected
c) histology
d) x-ray appearance

A
  • adolesence
  • knee
  • malignant mesenchymal cells

ALP+

  • elevated periosteum (Codman’s triangle), sunburst appearance
47
Q

Chondrosarcoma

A
  • >40y
  • axial skeleton/femur/tibia/pelvis
  • histology- malignant chondorcytes
  • x-ray: lytic with fluffy calcification, axial skeleton

**think older ppl tend to get in axial areas**

48
Q

Ewing’s sarcoma

A
  • age <20y
  • long bones , plevis
  • histology :sheets of small round cells, CD99+, t(11,22)
  • x-ray appearance: onion skinning of periosteum
49
Q

Giant cell tumour

A
  • 20-40y, F>M
  • Bone: knee (epiphysis)
  • Histology: osteoclast-type, multinucleate giant cells on bakcground of spindle/ovoid cells
  • X-ray appearance: lytic/lucent lesions right up to articular surface
50
Q

What is osteitis fibrosa cystica?

A

Changes due to bone resorption

51
Q

What is Pott’s disease?

A

TB of the spine

may result in psoas abscess and severe skeletal deformity

52
Q

most prevalent vector borne disease in the temperate Northern hemisphere

A

Lyme disease- spread by tick bites

organism: Borrelia burgdorferi

53
Q
A
54
Q

What are the benign bone tumours?

A
  1. osteoma
  2. enchondroma
  3. osteochondroma
  4. fibrous dysplasia
  5. simple bone cyst
  6. osteoblastoma
55
Q

Radiolucent nidus with sclerotic rim ‘Bull’s-eye

A

Osteoid osteoma (adolescence)

56
Q

What is gardner’s syndrome?

A
  1. GI polyps
  2. multiple osteomas
  3. epidermoid cysts
57
Q

What are the two types of osteoma?

A

a) adolescence (osteoid osteoma)

- pain at night, relived by aspirin

b) osteoma in middle age

58
Q

What’s the most common benign tumour of bone?

A

Osteochondroma

59
Q

Lytic lesion Cotton wool/popcorn calcification Expansile, O ring sign

A

Enchondroma

60
Q

Well defined bony protuberance from bone

Cartilage capped bony spur on surface of bone

‘mushroom’ on xray

A

Osteochondroma

61
Q

Soap bubble osteolysis
Shepherd’s crook deformity on x-ray

Chinese letter appearance on histology

A

Fibrous dysplasia

62
Q

Lytic well defined lesion

A

Simple bone cyst

63
Q

Speckled mineralisation

A

Osteoblastoma

64
Q

Which tumour is ALP+?

A

Osteosarcoma

65
Q

Buzzwords for benign bone diseases

A