Clinical Thyroid Disease Flashcards

1
Q

Name as many symptoms of hypothyroidism as you can (10)

A
Weight gain
Lethargy
Feeling cold
Constipation
Heavy periods
Dry skin/hair
Bradycardia
Slow reflexes
Goitre
Severe - puffy face, large tongue, hoarseness, coma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 3 types of hypothyroidism and where are they based?

A

Primary - thyroid
Secondary - pituitary
Subclinical - compensated

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

What are the thyroid function test results in each type of hypothyroidism?

A
Primary:
- Raised TSH; Low FT4 + FT3
Secondary:
- Low TSH; Low FT4 + FT3
Subclinical:
- Raised TSH; Normal FT4 + FT3
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the most common type of hypothyroidism?

A

Primary (only 1-2% secondary)

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

What is subclinical hypothyroidism?

A

An early, mild form of hypothyroidism

Normal FT4 and FT3 as TSH has managed to compensate (even the TSH is only lil bit above normal)

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

Is hypothyroidism more prevalent in women or men?

A

Women (1.9% v 0.1% in men)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What percentage of the population have subclinical hypothyroidism? What percentage or women over 60 have it?

A

5%

10%

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

What is the prevalence of congenital hypothyroidism?

A

1 in 3500 births

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

What problems can arise in congenital primary hympothyroidism?

A

DEVELOPMENTAL - agenesis/maldevelopment
DYSHORMONOGENESIS - trapping/organification of iodide/dehalogenase deficiency (deiodinase enzyme)

(‘growth retardation and mental retardation’)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do we screen for thyroid problems at birth?

A

Heel prick test

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

Give 4 general acquired causes of primary hypothyroidism

A
  • Autoimmune thyroid disease
  • Iatrogenic
  • Chronic iodine deficiency
  • Post-subacute thyroiditis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are types of autoimmune thyroid disease?

A

Hashimotos

Atrophic

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

What are the iatrogenic causes of primary hypothyroidism?

A
  • Post-op/post-radioactive iodine
  • External RT for H+N cancer
  • Antithyroid drugs, amiodarone, lithium, interferon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Give an example of post-subacute thyroiditis?

A

Post-partum thyroiditis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the major cause for secondary/tertiary hypothyroidism?

A

Pituitary/hypothalamic damage

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

Give 5 underlying causes for pituitary/tertiary hypothyroidism

A
  • Pit tumour
  • Craniopharyngioma
  • Post pit surgery or radiotherapy
  • Sheehan’s syndrome
  • Isolated TRH deficiency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is Sheehan’s syndrome?

A

Damage of pituitary gland during childbirth (due to low BP/haemhorrage during or post-partum)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Investigations for hypothyroidism?

A

TSH/fT4 (thyroid function tests)

Autoantibodies: TPO (thyroid peroxidase antibodies)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the standard treatment for hypothyroidism?

A

Levothyroxine (T4) tablets

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

What is the dosage plan for levothyroxine?

A

50mcg/day, increase after 2 weeks to 100mcg

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

For how long do u increase the dose of levothyroxine (T4)?

A

Until TSH is normal, or fT4 in normal range in secondary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How often should TSH be tested after stabilisation?

A

Annually

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

When should T4 be taken?

A

Same time everyday on empty stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Has there been any proven benefit to T3 treatment/T3 combined with T4?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

In what patients should you be more careful with treatment?

A

IHD
Pregnancy
Postpartum thyroiditis
Myxedema coma

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

What should be done in patients with IHD?

A

Start at lower dose 25mcg and increase cautiously (risk of angina/HF)

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

What should be done in patients who r pregnant?

A

Most will need an increase in LT4 dose (25%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What should be done in patients with post-partum thyroiditis?

A

Trial withdrawal and measure TFT’s in 6 wks

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

What should be done in patients with myxedema coma?

A

V rare emergency, may need IV T3 (steroid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

When should trial treatment for subclinical hypothyroidism be consdered?

A

TSH > 10
TSH > 5 w positive thyroid antibodies
TSH elevated with symptoms
Women pregnant/planning pregnancy

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

What is a normal FT4 and TSH level?

A

TSH: 0.3-3.3
FT4: 10-25

32
Q

Give 2 risk of over treatment for subclinical hypothyroidism

A

Osteopenia

Atrial fib

33
Q

Describe goitre

A

Swelling of thyroid gland causing swelling of neck

34
Q

Name 2 physiological causes of goitre

A

Puberty

Pregnancy

35
Q

Name 2 autoimmune causes of goitre

A

Graves

Hashimotos

36
Q

Name 2 forms of thyroiditis which cause goitre

A
Acute (de Quervain's)
Chronic fibrotic (Reidel's)
37
Q

Name 3 other causes of goitre

A

Iodine deficiency
Dyshormonogenesis
Goitrogens

38
Q

What are the types of goitre?

A
  • Multinodular
  • Diffuse (colloid, simple)
  • Cysts
  • Tumours
  • Misc (sarcoidosis, TB)
39
Q

What is there a risk of with a solitary nodule thyroid?

A

Malignancy - 5%

40
Q

In who is there a risk of malignancy associated with solitary nodule thyroid?

A

Children
Adults <30 or >60
Prev H+N irradiation
Pain, cervical lymphadenopathy

41
Q

What investigations are done for solitary thyroid nodules?

A

Thyroid function test
USS
FNA
Isotope scanning if low TSH - hot nodule

42
Q

What is the diff between hot and cold nodules?

A
Hot = producing too much hormone (to absorb iodine); hyperthyroidism
Cold = not producing any hormone (not absorbing iodine so not composed of thyroid cells); higher risk of cancer; cyst or adenoma
43
Q

What is the commonest form of thyroid cancer?

A

Papillary

44
Q

Describe the nature and spread of thyroid cancer?

A

Multifocal

Local spread to lymph nodes

45
Q

What is the prognosis like for papillary thyroid cancer?

A

Goood

46
Q

Describe the nature and spread of follicular thyroid cancer?

A

Usually single lesion

Mets through blood to lung/bone

47
Q

What is the prognosis like for follicular thyroid cancer?

A

Good if resectable

48
Q

What factors cause thyroid cancer prognosis to become poorer?

A
  • <16 yrs; >45yrs
  • spread outside capsule + mets
  • TNM stage
49
Q

What is the management plan for thyroid cancer?

A

Near total thyroidectomy (if high risk - lobectomy if low)
High dose radioiodine
Long term suppressive thyroxine
(DEBULK, DESTROY, SUPPRESS)
Follow up - thyroglobulin yrly; iodine scan of body

50
Q

What is there a risk of with overtreating of radioiodine?

A

Developing leukaemia - important to weigh up whether to leave someone w a lil bit of thyroid cancer n lower risk of leukaemia)

51
Q

Give 3 more rare thyroid cancers

A

Anaplastic
Lymphoma
Medullary

52
Q

What is the prognosis for anaplastic thyroid cancer?

A

V poor due to its aggressive and locally invasive nature

Doesnt respond to radioidone - external RT may help briefly

53
Q

How could thyroid lymphoma arise and how is it treated?

A

From pre-existing hashimotos

External RT w chemo

54
Q

What does medullary thyroid cancer arise from?

A

Parafollicular C cells; associated w MEN2

55
Q

What does medullary thyroid cancer cause in serum and what is the treatment?

A

Serum calcitonin levels raised

Treatment is total thyroidectomy, no radioiodine (variable prognosis)

56
Q

Name as many symptoms of hyperthyroidism as u can (10)

A
Weight loss
Anxiety/irritability 
Heat intolerance
Bowel infrequency 
Light periods
Sweaty palms
Palpitations 
Hyperreflexia/tremors
Goitre
Thyroid eye symptoms/signs
57
Q

What are the typical trends in thyroid function tests in hyperthyroidism?

A
T3/T4 = elevated
TSH = suppressed
58
Q

What are the commonest causes for primary hyperthyroidism?

A
  • Graves (70%)
  • Toxic Multinodular Goitre (20%)
  • Toxic adenoma
59
Q

What is a cause for secondary thyrotoxicosis?

A

Pituitary adenoma secreting TSH

60
Q

What are 2 causes of thyrotoxicosis w/o hyperthyroidism?

A
  • Destructive thyroiditis (post-partum, subacute (de Quervain’s), amiodarone)
  • Excessive thyroxine administration
61
Q

Which gender is graves disease more common in?

A

Women

62
Q

What type of condition is Graves

A

AUTOIMMUNE condition

63
Q

What antibodies are seen in Graves

A

Thyroid peroxidase

TSH receptor

64
Q

What are some presenting signs seen in Graves?

A

Exopthalmos (enlarged, red eyes)
Diffuse goitre
Hyperthyroid symptoms

65
Q

What is the most common cause of thyrotoxicosis in the elderly?

A

Multi-nodular goitre

66
Q

Discuss subacute (de Quervain’s) thyroiditis

A

<50 yrs
Viral trigger e.g. enterovirus
Painful goitre +/- fever/myalgia
May require short term steroids/NSAIDs

67
Q

Management of hyperthyroidism?

A

Beta blockers to manage symptoms
Anti-thyroid drugs
Radioiodine
Surgery (only large goitres/other options unavailable)

68
Q

What are the 2 ATDs?

A

Carbimazole (preferred)

Propylthiouracil (prefered in pregnancy)

69
Q

Side effects of ATDs?

A

Rash

Agranulocytosis 1:500 (potentially fatal - confirm patient has adequate neutrophil b4 treating)

70
Q

What is the usual ATD regimen?

A

Titration regimen; 12-18 months

71
Q

What are the selected cases for long term low dose ATD?

A
  • elderly
  • cardiac complications
  • unwilling for RAI
72
Q

Who cant radioiodine patients come into contact with for 4 wks?

A

<18 children

Pregnant women

73
Q

What is the risk of hypothyroidism in radioiodine treatment?

A

70%

74
Q

TSH: 15
FT4: 9
DIAGNOSIS?

A

Primary hypo
TSH raised
FT4 low
(TSH tried to produce more FT4 but the thyroid isn’t working so will not physically produce any more FT4)

75
Q

TSH: 0.5
FT4: 9
DIAGNOSIS?

A

Secondary hypo
TSH low side of normal
FT4 low

76
Q

TSH: 15
FT4: 12
DIAGNOSIS?

A

Subclinical hypo
TSH raised
FT4 normal