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Flashcards in Pathology Deck (57)
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1
Q

What auto-antibodies are associated with RA and each of the connective tissue diseases?

A
Rheumatoid arthritis – Anti-CCP 
Lupus – Anti-dsDNA
Sclerosis - Limited - Anti centromere
                - Diffuse - Anti-Scl-70 
Dermatomyositis – Anti Jo
Sjogrens – Anti Ro La
2
Q

Describe the difference in pathology of rheumatoid arthritis

A

Acute phases:

  • Pannus formation – inflammatory granulation tissue
  • Hyperplastic / reactive synovium

Chronic phase:

  • Fibrosis
  • deformity
3
Q

Give examples of three metabolic conditions which have MSK consequences

A

Pagets

Osteomalacia

Crystal arthropathies

4
Q

What processes allow the formation of uric acid crystals?

A

Uric acid is the end-product of purine synthesis

Adenine (A) and guanine (G) are purine based

=> urate is formed in DNA replication

5
Q

What are the two main reasons for which hyperuricaemia would occur?

A

Increased production
Or
Reduced excretion

6
Q

For what reasons would the body produce more uric acid than normal?

A

Idiopathic - unknown enzyme defect (90%)

Known enzyme defect - HGPRT deficiency
(Lysch Nyhan syndrome)

Increased cell turnover

  • Psoriasis
  • Cancer
7
Q

What can be responsible for under excretion of uric acid?

A

Drug side effect

=> thiazide diuretics reduce urate excretion

8
Q

In what joints do the uric acid crystals usually deposit?

A

joints at lower temperatures than core body temperature

9
Q

What secondary degenerative changes can gout cause?

A

Deposition in soft tissues – gouty tophus

Renal disease – stones and direct deposition in tubules and interstitium

10
Q

What features would be seen on histology of a sample with gout?

A

Amorphous eosinophilic debris and inflammation
(giant cells)

Crystals LOST during tissue processing

11
Q

In what individuals does pseudogout usually present?

A

Usually older individuals in their large joints

12
Q

What can cause pseudogout?

A

Usually idiopathic

known causes:
hypercalcaemia (inc. hyperparathyroidism), haemachromatosis
hypomagnesaemia
ochronsis
hypothyroidism
13
Q

What shape do pseudogout crystals appear on microscopy?

A

Rhomboid shaped crystals

Thicker and bigger than needle shaped urate crystals

14
Q

What is Paget’s disease of bone?

A

Abnormality of bone turn-over
=> Increased osteoclastic activity
more bone but not normally structured

15
Q

What can predispose to Paget’s disease?

A

Genetic factors

Viruses:

  • paramyxovirus
  • measles
  • Resp. Syncytial Virus
16
Q

What are the three stages in Paget’s disease?

A

Osteolytic
mixed
burnt out

17
Q

What is the end result in Paget’s disease?

A

thick excess bone

abnormal reversal lines – mosaic pattern

18
Q

What bones does Paget’s disease affect?

A

Can affect ALL bones usually axial, small bones less commonly affected

19
Q

What can cause pain in Paget’s disease?

A

microfracture or nerve compression

20
Q

What secondary problems can Paget’s disease cause?

A

Increased metabolism
=> heat, warm skin,
AV shunt effectively high output heart failure

Secondary malignancy – osteosarcoma

21
Q

What is osteomalacia?

A

Abnormal vitamin D metabolism
Sun exposure related

Causes:

  • Rickets in young pts
  • Bowed legs, square heads, pigeon chest, rickety rosary
22
Q

Describe the simple pathogenesis of a fracture

A

Trauma
Bone breaks – pain from periosteum
Haemorrhage
Remember – rubor, calor, tumour and dolor

23
Q

At what stage after a bone is fractured, does the callus reach its maximum girth

A

2-3 weeks

24
Q

What can cause a pathological fracture

A

Osteoporosis is very common
Tumours
Benign - usually children and primary
Malignant – adults and metastatic

25
Q

What cancers commonly metastasize to bone?

A
Breast
Bronchus
Lung
Prostate
Thyroid
Renal
26
Q

What conditions can cause bony lesions?

A

myeloma/plasmacytoma

Malignant proliferation of plasma cells. Causes bony lesions

27
Q

What is avascular necrosis?

A

Bone infarction

28
Q

What can cause avascular necrosis?

A
trauma (scaphoid)
alcohol
dysbarism
Steroid injection
sickle cell disease,
infection
29
Q

How do subchondral cysts form?

A

synovial fluid through bone forming small cysts

30
Q

Why do osteophytes form in degenerative diseases such as osteoarthritis?

A

remodelling of bone to cope with stress

Remodelling = disorganised and produces abnormal outgrowths - osteophytes

31
Q

Give examples of benign tumours of bone

A

Ganglion Cyst
Giant cell tumour
Fibromatosis
Fibrous dysplasia

32
Q

Where does a ganglion cyst usually present?

A

peripheral lump
near a joint capsule or tendon sheath
Common around the wrist

33
Q

Why is a ganglion cyst not a true cyst?

A

It has no epithelial lining

34
Q

How do ganglion cysts appear histologically?

A
  • space with myxoid material

- Secondary inflammatory changes

35
Q

Give some examples of common superficial fibromatoses

A

Dupuytren’s
Knuckle pads
Plantar
Penile – Peyronie’s

36
Q

How do deep fibromatoses differ from superficial fibromatoses?

A
  • Mesenteric or pelvic
  • Desmoid tumours
  • Association with Gardner’s Syndrome
37
Q

Where can giant cell tumours present?

A

Pigmented villonodular synovitis – present in large joints

Giant cell tumour of tendon sheath – present in small joints e.g. digits

38
Q

Giant cell tumours in large joints are more easily excised than those in smaller joints. TRUE/FALSE?

A

FALSE

small nodules are easily excised (with occasional recurrence)

PVNS – more destructive and diffuse in a joint space. Difficult to excise and can often recur.

39
Q

How do angiolipomas usually present?

A

multiple and peripheral

painful subcutaneous lesion

40
Q

A leiomyoma is a tumour of what?

A

Smooth muscle

=> Can arise from large vessel walls (e.g. muscular veins)

41
Q

What rare benign tumour can occur from skeletal muscle?

A

Rhabdomyomas

42
Q

What is the name given to a benign tumour of cartilage?

A

Enchondroma

43
Q

Where do simple osteomas usually present?

A

In the cranial bones

=> lumps often seen on forehead of patient

44
Q

What name is given to the condition where a patient present with multiple osteomas?

A

Gardner’s syndrome

45
Q

What age group are most commonly affected by Osteosarcoma?

A

paediatric age-group

occurs in Long bones

46
Q

How is an osteosarcoma defined?

A

malignant tumour that produces osteoid is an osteosarcoma until proven otherwise

47
Q

Who is most likely to be affected by Ewing’s sarcoma?

A

children and adolscents

48
Q

Where do Ewing’s sarcomas commonly affect?

A

Any soft tissue or bony location

=> often long bones in adolescents

49
Q

Ewing’s sarcomas are destructive, rapidly growing and highly malignant. TRUE/FALSE?

A

TRUE

50
Q

What cells are thought to mutate and give rise to Ewing’s sarcomas?

A

primitive mesenchymal or neuroectodermal cell

51
Q

How do Ewing’s sarcomas appear in clinic?

A

Small round blue cell tumours

52
Q

What type of cancer do you always want to exclude?

A

Carcinoma group:

  • Sarcomatoid carcinoma
  • carcinosarcoma
  • metaplastic carcinoma
53
Q

What is a Pseudosarcoma?

A

Tissues undergoing repair often appear very atypical and the diagnosis can be very difficult

54
Q

What reactive lesion appears histologically as a chaotic appearance with haemorrhage, pseudocystic spaces and large atypical cells?

A

Nodular Fasciitis

55
Q

What is Myositis ossificans?

A

A reactive lesion which affects large muscles:

  • quadriceps
  • gluteus
  • brachialis (occasionally)
56
Q

Chondrosarcomas affect what parts of the body?

A
Axial skeleton (pelvis)
Head and Neck

NOT common in peripheries

57
Q

Where do rheumatoid nodules usually present, and what are they?

A

Elbow

Necrobiotic granulomatous inflammation