Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

YEAR 5: Histopathology > Histo: Bone Pathology > Flashcards

Histo: Bone Pathology Flashcards

1
Q

What are the main functions of bone?

A
  • Mechanical - support and site for muscle attachment
  • Protective - vital organs and bone marrow
  • Metabolic - store of calcium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Outline the composition of bone.

A

Inorganic (65%) - Calcium hydroxyapatite.
Storehouse of 99% of body calcium, 85% of the phosphorus, 65% of sodium and magnesium

Organic (35%) - bone cells and protein matrix (mainly type 1 collagen)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

In which part of a bone is the growth plate found?

A

Metaphysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the main features of cortical bones?

A
  • Long bones
  • 80% of skeleton
  • Appendicular
  • 80-90% calcified
  • Mainly mechanical and protective
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the main features of cancellous bones?

A
  • Vertebrae and pelvis
  • 20% of skeleton
  • Mainly axial
  • 15-25% calcified
  • Mainly metabolic
  • Large surface

Cancellous bone is metabolically more active than cortical.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the three main types of bone cell and what are their roles?

A
  • Osteoblasts - build bone by laying down osteoid
  • Osteoclasts - multinucleate cells of the macrophage family that resorb bone
  • Osteocytes - osteoblasts-like cells that sit in the lacunae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How are osteoclasts regulated?

A

Osteoblasts produce RANKL and osteoprotegrin
- RANKL - stimulates osteoclast differentation and activity
- Osteoprotegerin - blocks RANK thus inhibiting osteoclast differentiation and activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define metabolic bone disease.

A

A group of diseases characterised by disordered bone turnover due to imbalance of various body chemicals.

NOTE: overall effect tends to be osteopaenia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the three main categories of metabolic bone disease?

A
  • Non-endocrine (e.g. age-related)
  • Endocrine (e.g. vitamin D, PTH)
  • Disuse osteopaenia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where is bone usually sampled from for histological analysis of bone in metabolic bone disease?

A

Iliac crest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which static parameters are measured in the histological analysis of bone in metabolic bone disease?

A
  • Cortical thickness and porosity
  • Trabecular bone volume
  • Thickness, number and separation of trabeculae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which technique is used to measure histodynamic parameters when investigating metabolic bone disease?

A

Fluorescent tetracycline labelling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the most common causes of osteoporosis?

A

90% are due to insufficient calcium intake or post-menopausal oestrogen deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

List some primary and secondary causes of osteoporosis.

A
  • Primary - age, post-menopause
  • Secondary - medication (steroids), systemic disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

List some risk factors for osteoporosis

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the ways in which osteoporosis can present.

A

Asymptomatic - usually presents with pathological fractures

  • Wrist - Colles’
  • Hip - NoF and intertrochanteric
  • Pelvic
  • Vertebral (60% asymptomatic) - compression fractures in T11-L1
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which investigations may be used in a patient with suspected osteoporosis?

A

Biochemical

  • Serum calcium, phosphate and ALP (should be NORMAL)
  • Urinary calcium
  • Collagen breakdown products

Imaging

DEXA

  • Osteopenia = T score 1-2.5 SD below normal
  • Osteoporosis = T score >2.5 below normal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which four organs are affected by PTH and have a role in calcium homeostasis?

A
  • Kidney
  • Bone
  • Proximal small intestine
  • Parathyroid gland
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the most common cause of hypocalcaemia?

A

Vitamin D deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Define osteomalacia.

A

Defective bone mineralisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What two underlying electrolyte abnormalities can cause osteomalacia?

A
  • Deficiency of vitamin D
  • Deficiency of phosphate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the main histological feature of osteomalacia?

A

Reduced amount of mineralised bone compared to the amount of osteoid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

List some signs and symptoms of osteomalacia.

A
  • Bone pain/tenderness
  • Fracture
  • Proximal weakness
  • Bone deformity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Name some radiological features of osteomalacia.

A
  • Bowing of the legs (rickets)
  • Metaphysial cupping and fraying (rickets)
  • Horizontal pseudofractures (Looser zone)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Describe how the urine excretion of calcium and phosphate changes in primary hyperparathyroidism.

A

Both increase

NOTE: PTH causes a minor increase in reabsorption of calcium from the urine, however, as it causes a large increase in serum calcium concentration (and hence an increase in the calcium concentration of the glomerular filtrate) it causes an overall increase in urine calcium excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What skeletal change is seen in primary hyperparathyroidism?

A

Osteitis fibrosa cystica (brown tumours on X-ray)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

List the main primary and secondary causes of hyperparathyroidism.

A

Primary

  • Parathyroid adenoma (90%)
  • Chief cell hyperplasia

Secondary

  • CKD
  • Vitamin D deficiency
  • Malabsorption
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What histological feature is typically seen in hyperparathyroidism?

A

Brown cell tumour - several multinucleated giant cells (osteoclasts) on a background of fibrous stroma with haemorrhage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Define renal osteodystrophy.

A

Term used to describe all the skeletal changes of chronic renal disease:

  • Increased bone resorption (osteitis fibrosa cystica)
  • Osteomalacia
  • Osteosclerosis
  • Osteoporosis
  • Growth retardation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is Paget’s disease and what are its three phases?

A

Disorder of bone turnover

Three phases:

  1. Osteolytic
  2. Osteolytic-osteosclerotic
  3. Quiescent osteosclerotic

NOTE: the combination of osteoblast and osteoclast activity results in new bone formation

NOTE: 85% are polyostotic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Describe the histological appearance of Paget’s disease.

A

Mosaic pattern of randomly organised lamellar bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Which viruses are associated with Paget’s disease?

A

Paramyxoviruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Describe the presentation of Paget’s disease.

A
  • Pain
  • Microfractures
  • Deformity - bowing of tibia
  • Nerve compression - spinal nerves and cord
  • Skull changes - can put medulla at risk

Can also cause haemodynamic changes and high output heart failure

Development of sarcoma in area of involvement 1%

34
Q

Which bones are most affected by Paget’s?

A

Skull
Vertebrae
Pelvis
Femur
Tibia

35
Q

What are the four stages of fracture repair?

A
  • Organisation of a haematoma at the site of the fracture (pro-callus)
  • Formation of a fibrocartilaginous callus
  • Mineralisation of the fibrocartilaginous callus
  • Remodelling of the bone along weight-bearing lines
36
Q

List some factors that influence fracture healing.

A
  • Type of fracture
  • Presence of infection
  • Pre-existing systemic conditions (e.g. chronic conditions)
37
Q

Which sites are most commonly affected by osteomyelitis?

A
  • Vertebra
  • Jaw (secondary to dental abscess)
  • Toe (secondary to diabetic skin ulcer)
  • Long bones (usually metaphysis)
38
Q

Describe the typical presentation of osteomyelitis.

A

General - malaise, fever, rigors, leukocytosis

Local - pain, swelling, redness

39
Q

Which investigations may be used in suspected osteomyelitis?

A
  • Blood cultures (positive in 60%)
  • X-ray (will eventually show lytic areas)
40
Q

What are the routes of infection in osteomyelitis?

A
  • Haematogenous
  • Direct extension
  • Traumatic (penetrating injury)
41
Q

Which organisms can cause osteomyelitis?

A
  • Staphylococcus aureas (90%)
  • E. coli
  • Klebsiella
  • Salmonella (SCD)
  • Pseudomonas (IVDU)

Osteomyelitis is almost always bacterial (rarely fungal)

42
Q

When do X-ray changes appear in osteomyelitis and describe them?

A

Usually appear about 10 days after onset

  • Mottled rarefaction and lifting of periosteum
  • First week changes - involucrum formation
  • Later changes - irregular lytic destruction
  • Sequestra may form after 3-6 weeks
43
Q

What are involucrum and sequestra?

A

Involucrum - bone that has formed around an area of dead necrotic bone (analogous to an abscess in soft tissue)

Sequestra - a piece of dead bone that has been separated off (can be a foci of infection)

44
Q

What are the potential consequences of TB osteomyelitis of the vertebrae?

A
  • May result in psoas abscess or severe skeletal deformity
  • TB osteomyelitis tends to only occur in immunocompromised patients
  • Systemic amyloidosis may occur in some cases

Called Pott’s disease

45
Q

Describe the histological appearance of TB osteomyelitis.

A
  • Lots of inflammatory cells can be seen in between trabeculae
  • Langhans giant cells (with a horse-shoe nucleus) can be seen
46
Q

What congenital skeletal lesions are associated with syphilis?

A
  • Osteochondritis
  • Osteoperiositis
  • Diaphyseal osteomyelitis
47
Q

List some acquired skeletal lesions that are associated with syphilis.

A
  • Non-gummatous periostitis
  • Gummatous inflammation of joints and bones
  • Neuropathic joints (tabes dorsalis)
  • Neuropathic shaft fractures
48
Q

What is Lyme disease?

A
  • Inflammatory arthropathy that occurs as part of a complex multisystem illness from a tick bite
49
Q

What is the organism and vector in lyme disease?

A

Organism: Borrelia burgdorferi (deer tick)

Vector: Ixodus dammini/scapularis

50
Q

What is the skin rash that is classically associated with lyme disease?

A

Erythema chronicum migrans

51
Q

Describe the clinical features of Lyme disease at different stages

A
  • Early localised - flu-like symptoms with rash (90%) often on thigh, groin or axilla, 1-50 cm in diameter
  • Early disseminated - affects many organs (musculoskeletal, heart, nervous system)
  • Late, persistent - dominated by arthritis
52
Q

Outline the diagnosis and treatment of lyme disease.

A
  • Diagnosis is often clincial but can use ELISA if there is no erythema migrans
  • Treat with antibiotics (doxycycline)
53
Q

What is the difference between primary and secondary osteoarthritis?

A

Primary - age-related

Secondary - can occur at any age, occurs in a previously damaged or congenitally abnormal joint

54
Q

What happens to the joint in OA?

A
  • Cartilage degeneration
  • Fissuring
  • Abnormal matrix calcification
  • Osteophyte formation

Synovium becomes inflamed with inflammatory cell infiltrate

55
Q

What are the main sites affected by osteoarthritis?

A
  • Vertebrae
  • Hips
  • Knees
  • DIP and PIP of the hand
56
Q

What are the HLA associations of rheumatoid arthritis?

A

HLA DR4 and HLA DR1 (Chr6p21)

57
Q

What is rheumatoid factor and what proportion of patient’s are rheumatoid factor positive?

A
  • IgM antibody against IgG
  • 80% of patients are RF positive
  • Circulating immune complexes may be responsible for extra-articular disease
58
Q

Which sites tend to be affected by rheumatoid arthritis?

A
  • Small joints of the hand and feet (sparing the DIP)
  • Wrists, elbows, ankles and knees
  • Usually a slowly progressing, symmetrical pattern

Patients can also get rheumatoid nodules in the skin (25%)

59
Q

List some characteristic deformities associated with rheumatoid arthiritis.

A
  • Radial deviation of the wrist
  • Ulnar deviation of the fingers
  • Swan neck and Boutonnier deformity
  • Z-shaped thumb
60
Q

Describe the histological features of rheumatoid arthritis.

A
  • Proliferative synovitis
  • Thickening of synovial membranes
  • Hyperplasia of surface synoviocytes
  • Intense inflammatory cell infiltrate
  • Fibrin deposition
  • Necrosis
  • A pannus can form (exuberant inflamed synovium)
61
Q

Which type of multinucleate giant cell may be seen in rheumatoid arthritis?

A

Grimley-Sokoloff cell (like a Langhans giant cell but does not have horseshoe nuclei)

62
Q

What type of crystals cause gout?

A

Needle-shaped negatively birefringent urate crystals

NOTE: big toe is involved in 90% of cases

NOTE: a tophus is pathognomonic of gout

63
Q

Which crystals cause pseudogout? Describe them

A

Calcium crystals

  • Calcium pyrophosphate - mainly knees
  • Calcium phosphate (hydroxyapatite) - knees and shouldrs

Crystals are rhomboid-shaped and positively birefringent

64
Q

Which tumours most commonly metastasis to the bone in:

  1. Adults
  2. Children
A

Adults:

  • Breast
  • Prostate
  • Lung
  • Kidney
  • Thyroid

Children:

  • Neuroblastoma
  • Wilm’s tumour
  • Osteosarcoma
  • Ewing’s
  • Rhabdomyosarcoma
65
Q

Name three types of primary malignant bone tumours.

A
  • Osteosarcoma
  • Chondrosarcoma
  • Ewing’s sarcoma/PPNET
66
Q

What are the key epidemiological and radiological features of osteosarcoma?

A

Most common primary bone tumour

Incidence peaks in adolescence

60% of cases affect the knee

X-ray: usually metaphysial, lytic, permeative, elevated periosteum (Codman’s triangle)

67
Q

Describe the histological appearance of osteosarcoma.

A

Malignant mesenchymal cells with or without bone and cartilage formation

68
Q

What are the main epidemiological, clinical, radiological, and histological features of chondrosarcoma?

A

Malignant cartilage producing tumour

Typically affects >40 years

Affects axial skeleton, proximal femur and proximal tibia

X-ray: lytic with fluffy calcification

Histology: malignant chondrocytes with or without chondroid matrix

69
Q

What are the main epidemiological, clinical, radiological, and histological features of Ewing’s sarcoma?

A

Highly malignant small round cell tumour

Typically affects <20 years

Mainly affect diaphysis and metaphysis of long bones, pelvis

X-ray: onion-skinning of the periosteum, lytic with or withour sclerosis

Histology: sheets of small round cells

Specific chromosomal translocation - 11;22 (EWS/FLI1)

70
Q

Which chromosomal translocation is associated with Ewing’s sarcoma?

A

11;22 (ESWR1:Fli1)

71
Q

What type of bone is lost in osteoporosis?

A

Cancellous

72
Q

What would be the characteristic appearance of gout on x-ray?

A

“Rat-bite erosions”

73
Q

What would be the characteristic appearance of pseudogout on x-ray?

A

White lines of chondrocalcinosis

74
Q

When is syphilis osteomyelitis typically seen?

A

As a result of congenital infection

75
Q

What bacterial agents typically cause osteomyelitis in children?

A

Aside from staph aureus, Haemophilus influenzae (Hib) and Group B strep are also common

76
Q

What are Bouchard’s nodes?

A

Nodes of the PIPJ, characteristic of OA

77
Q

What are Herbeden’s nodes?

A

Nodes of the DIPJ, characteristic of OA

78
Q

What are the characteristic X-ray findings of osteoarthritis?

A

LOSS
Loss of joint space
Osteophytes
Subchondral sclerosis
Subchondral cysts

79
Q

What is meant by ‘swan-neck deformity’?

A

Hyperextension of PIPJ and flexion of DIPJ

80
Q

What is meant by ‘Boutonniere’ deformity?

A

Flexion of PIPJ and hyperextension of DIPJ

YEAR 5: Histopathology (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions