Thyroid pathology Flashcards Preview

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Flashcards in Thyroid pathology Deck (93):
1

What are the three embryological abnormalities of the thyroid gland?

Lingual thyroid gland
Thyroglossal duct cyst
Retrosternal thyroid gland

2

How is the thyroid gland arranged histologically?

Follicles containing thyroglobulin and lined by follicular epithelium
Scattered C cells/parafollicular cells

3

What do C cells secrete?

Calcitonin

4

What does calcitonin do?

Reduces blood calcium levels (minimally relevant)

5

Which thyroid-related hormone is secreted from the hypothalamus to act on the anterior pituitary?

Thyrotropin releasing hormone

6

Which thyroid-related hormone is secreted from the anterior pituitary to act on the thyroid?

Thyroid stimulating hormone

7

Which hormones are secreted from the thyroid in response to hormonal stimulation from the pituitary?

Triodothyronin (T3)
Thyroxine (T4)

8

Which specific cells of the thyroid does thyroid stimulating hormone act on?

Thyroid follicular epithelium

9

Which receptor does thyroid stimulating hormone bind to? Where is this receptor found?

TSH receptor on follicular epithelium

10

Which type of receptor is TSH receptor?

G-protein coupled receptor

11

How do G-protein coupled receptors work?

Convert GTP to GDP to produced cAMP which increases the production of thyroid hormones

12

T3 and T4 only circulate when bound to plasma proteins. T/F

False - they exist in bound or free forms

13

How do T3/4 work on target tissues?

Bind to target cells >
Bound T3/4-receptor complex translocates to the cell nucleus >
Binding to thyroid response elements on target genes >
Gene transcription and increase in BMR

14

When might the thyroid gland atropy?

When its function is reduced

15

Enlarged thyroid glands are capable of causing breathing and/or swallowing difficulties. T/F

True - if thyroid glands enlarge enough they can cause local mass effects

16

Define the terms thyrotoxicosis and hyperthyroid

Thyrotoxicosis - too much thyroid hormone
Hyperthyroid - hyper function of the thyroid tissues

17

Is there a genetic component to autoimmune thyroid disease?

Yes

18

What autoimmune condition is associated with autoimmune thyroid disease?

Vitiligo

19

What is the most common cause of hyperthyroidism?

Grave's disease

20

What is a pituitary cause of thyrotoxicosis?

TSH secreting pituitary adenoma

21

Name a cause of ectopic thyrotoxicosis

Struma ovarii

22

Grave's disease is autoimmune. T/F

True

23

Is graves disease more common in woman or men?

Woman

24

What age group typically presents with Grave's disease?

20-40 y/o

25

What are the antibodies against in Grave's disease?

Thyroid stimulating hormone receptor
Thyroglobulin
Thyroid peroxisomes

26

Name an anti TSH receptor antibody involved in Grave's

Thyroid stimulating immunoglobulin

27

What is the triad of features found in Grave's disease?

Hyperthyroidism with diffuse goitre
Exopthalamos (TED)
Pretibial myxoedema

28

Why do you get thryoid eye disease in Grave's?

Fibroblasts within the eye and surrounding tissues express TSH receptors

29

What is the most common cause of hypothyroidism?

Hashimoto's thyroiditis

30

Is hashimoto's thyroiditis autoimmune?

Yes

31

Who typically gets Hashimoto's thyroiditis?

Middle aged woman

32

Is Hashimoto's thyroiditis associated with other autoimmune conditions? Is it associated with HLA?

Yes & yes

33

What are secondary and tertiary causes of hypothyroidism?

Pituitary tumour
Hypothalamic tumour

34

What are other causes of hypothyroidism?

Iodine deficiency
Lithium medication
Iatrogenic (hyperthyroidism treatment)

35

Is hashimoto's thyroiditis more common in woman or men?

Women

36

What is the typical age range who gets hashimoto's thyroiditis?

45-60 y/o

37

Does hashimoto's thyroiditis have a genetic component?

Yes

38

What anti-thyroid antibodies are associated with hashimoto's thyroiditis?

Anti-thyroglobulin
Anti-peroxisome

39

What is hashitoxicosis?

Transient hyperthyroidism that can precede hashimoto's thyroiditis

40

Which two things is hashimoto's thyroiditis associated with?

Autoimmune conditions
B cell non-hodkin's lymphoma

41

What is a goitre?

Enlargement of the thyroid gland

42

Which dietary deficiency is goitre/goitre-producing conditions associated with?

Iodine

43

What is the typical pathogenesis of goitre?

Reduced thyroid hormones >
TSH increased and results in enlarged gland >

44

How does a hypothyroid goitre occur?

Compensation for reduced thyroid hormone fails resulting in hypothyroid goitre

45

What is the term for a state of normal thyroid hormone levels?

Euthyroid

46

Doe males or females get diffuse goitre more commonly?

Females

47

Why might adolescents/young adults present with diffuse goitre?

Dyshormonogenesis (errors of metabolism)

48

How do young patients with diffuse goitre typically present?

Euthyroid with mass effect symptoms (subclinical hypothyroid)

49

What may dyshormonogensis' cause in children?

Cretinism

50

Can multi-nodular goitre evolve from a long standing diffuse goitre?

Yes

51

What mass effects can goitre cause?

Dysphagia
Difficulty breathing
Vessel compression

52

What is the risk of malignancy with a multinodular goitre?

Low but present

53

Which cells do follicular and papillary thyroid carcinomas come from?

Follicular

54

Which cells does medullary thyroid carcinoma come from?

Parafollicular C cells

55

How do follicular adenomas present?

Discrete solitary mass +/- local symptoms if large

56

Are thyroid adenomas functional?

Most are not
Those which are most often cause hyperthyroid (TSH independent)

57

What is follicular adenoma often mistaken for?

Dominant nodule in multinodular goitre
Follicular carcinoma

58

Do males or females more commonly get thyroid cancer?

Females (apart from children and elderly)

59

When do thyroid cancers present?

Early adulthood

60

What is papillary cancer associated with?

Radiation

61

What is follicular cancer associated with?

Iodine deficiency

62

What is medullary cancer associated with?

Multiple endocrine neoplasia type 2
Familial medullary cancer

63

What type of goitre does papillary cancer cause?

Solitary thyroid nodule - multifocal, cystic, calcified

64

Does papillary cancer spread by lymph or blood?

Lymph

65

Does follicular cancer spread by lymph or blood?

Blood

66

How does papillary cancer typically present?

Hoarseness
Dysphagia
Cough
Dysphonia

67

What type of goitre does follicular cancer cause?

Slowly enlarging, painless, solitary nodule

68

Where does follicular cancer tend to spread?

Bones, lungs, liver

69

What age group typically gets follicular cancer?

Middle aged

70

How common is medullary thyroid cancer?

Rare

71

What can medullary thyroid cancers secrete?

Calcitonin

72

In which scenario would a medullary cancer arise in a 1) young patient and 2) an adult?

1 - MEN
2 - Familial/sporadic

73

What is the difference between sporadic and familial medullary cancer cases?

Sporadic - solitary nodule
Familial - bilateral/multicentric

74

How does medullary cancer present?

Hoarseness
Airway compression
Dysphagia
Diarrhoea
Cushings

75

What causes paraneoplastic 1) diarrhoea and 2) cushings?

1 - VIP
2 - ACTH

76

What is the most aggressive thyroid cancer?

Anaplastic

77

In which age range does anaplastic cancer present?

Elderly

78

Which cancer occurs in people with a history of thyroid cancer?

Anaplastic

79

How is thyroid cancer classified?

Th1 - repeat test
Th2 - benign
Th3 - atypia probably benign
Th4 - atypia probably malignant
Th5 - malignant

80

How many parathyroid glands are there?

4

81

Which cells compose the parathyroid glands?

Chief cells and oxyphil cells

82

What do chief cells secrete and what is its effect?

Parathyroid hormone affecting calcium metabolism

83

What is the most common cause of hyperparathyroidism?

Parathyroid adenoma

84

What is parathyroid hyperplasia associated with?

Multiple endocrine neoplasia 1 & 2

85

What is the difference in terms of gland involvement between parathyroid adenomas and hyperplasia

Adenoma - one gland involved and others atrophic
Hyperplasia - all glands involved

86

What chronic metabolic state can cause secondary hyperparathyroidism?

Hypocalcaemia

87

What are the two most common causes of chronic hypocalcaemia?

Renal failure
Vitamin D deficiency

88

What is tertiary hyperparathyroidism associated with?

Hypercalcaemia

89

What is the presentation of hyperparathyroid disease?

Bone (pain, fracture, osteoporosis)
Nephrolithiasis (kidney stones)
GI complications (constipations, nausea, gall stones)
CNS (depression)
Neuromuscular (weakness, fatigue)
CVS (calcification of aortic and mitral valves)

90

How common is hypoparathyroid?

Very rare

91

What are the common causes of hypoparathyroid?

Iatrogenic (post-surgery)
Di George syndrome (congenital)
Familial

92

What are the associations with familial hypoparathyroidism?

Adrenal insufficiency
Mucocutaneous candidiasis

93

How does hypoparathyroid present?

Tetany
Altered mental state
Parkinsonian
Raised ICP --> papilloedema
Calcification of lens and cataracts
Dental abnormalities (if during development)

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