pathology of thyroid

Question 1

what are some embryological abnormalities of thyroid

Answer 1

• failure of descent
• excessive descent
• thyroglossal duct cyst

Question 2

what is the thyroid composed of

Answer 2

lobules

Question 3

what is in the centre of each follicle

Answer 3

dense amorphous pink material containing thyroglobulin

Question 4

thyroid function

Answer 4

• TRH from hypothalamus stimulates release of TSH from cells in anterior pituitary gland.
• TSH binds to TSH receptor on surface of thyroid epithelial cells.
• G proteins activated with conversion of GTP to GDP and production of cAMP.
• cAMP increases production and release of T3 and T4.
• T3 and T4 circulate in bound and free forms
• On release T3 and T4 bind to receptor in target cells

Question 5

what comes under thryoiditis

Answer 5

hypo and hyperthyroidism

Question 6

what autoimmune disease presents with hypofunction

Answer 6

hashimoto thyroiditis

Question 7

what autoimmune disease presents with hyperfunction

Answer 7

grave’s disease

Question 8

which genes are involved in autoimmune thyroiditis

Answer 8

• CTLA-4

- PTPN-22

Question 9

which haplotype is autoimmune thyroiditis associated with

Answer 9

HLA

Question 10

what is Hashimoto’s thyroiditis

Answer 10

gradual destruction of thyroid tissue

• 45-60yrs
• genetic

Question 11

what is present in Hashimoto’s that characterises it

Answer 11

anti-thyroid antibodies

-CD8 +ve T cells may mediate destruction of thyroid epithelium

Question 12

signs of hashimoto’s

Answer 12

• thyroid may be enlarged
• prominent lymphoid infiltrate
• thyroid follicles atrophy
• may see progressive fibrosis

Question 13

what are symptoms and signs due to in hypothyroidism

Answer 13

low levels of T3 and T4

Question 14

who usually gets hashimoto’s

Answer 14

middle aged women

Question 15

other causes of hypothyroidism

Answer 15

• iodine deficiency
• drugs
• post therapy
• congenital abnormalities
• in born errors of metabolism

Question 16

what may hashimoto’s be preceded by

Answer 16

transient hyperfunction

Question 17

what are people with hashimotos at increased risk of

Answer 17

• other autoimmune disease

- B cell NHL in the thyroid gland (lymphoma)

Question 18

what antibodies are present in Grave’s disease

Answer 18

• antibodies to TSH receptor, thyroid peroxisomes and thyroglobulin
• anti TSH receptor antibodies

Question 19

what are symptoms due to in hyperthyroidism

Answer 19

excess T3 and T4

Question 20

other causes of hyperthryoidism

Answer 20

• thyroiditis
• ectopic production
• Factitious

Question 21

features of Grave’s

Answer 21

• Hyperthyroidism with diffuse enlargement of the thyroid
• Eye changes (exophthalmos)
• Pretibial myxoedema.

Question 22

what is Goitre

Answer 22

any enlargement of the thyroid gland

Question 23

what causes Goitre

Answer 23

-reduced T3/T4 production which causes rise in TSH, stimulating gland enlargement

Question 24

what is there high levels of in diffuse Goitre

Answer 24

TSH

Question 25

effects of a multi-nodular goitre

Answer 25

- cosmetic - airway obstruction - dysphagia - compress vessels

Question 26

adenoma of thyroid gland

Answer 26

follicular adenoma

Question 27

carcinomas of thyroid gland

Answer 27

- papillary - follicular - anaplastic - medullary

Question 28

what are the adenomas encapsulated by

Answer 28

Encapsulated by a surrounding collagen cuff

Question 29

what can adenomas secrete

Answer 29

thyroid hormones - thyrotoxicosis

Question 30

where are mutations in adenomas

Answer 30

TSHR signalling pathway

Question 31

who gets thyroid cancer

Answer 31

any age | mainly female

Question 32

most common carcinoma of thryoid

Answer 32

papillary

Question 33

where are most of the carcinomas derived from

Answer 33

follicular epithelium | medullary carcinoma is from C cells

Question 34

what are the environmental associations with carcinoma

Answer 34

``` Ionising radiation (papillary carcinoma) Iodine deficiency (follicular carcinoma) ```

Question 35

metastases of papillary carcinoma

Answer 35

lymph nodes

Question 36

presentation of papillary carcinoma

Answer 36

- lesion in thyroid gland - hoarseness - dysphagia - cough - dyspnoea - sometimes haematogenous spread

Question 37

features of follicular carcinoma

Answer 37

- slowly enlarging - painless - non-functional

Question 38

what is medullary carcinoma associated with

Answer 38

multiple endocrine neoplasia

Question 39

what is medullary carcinoma composed of

Answer 39

Composed of spindle or polygonal cells arranged in nests, trabeculae or follicles associated with amyloid deposition

Question 40

presentation of medullary carcinoma

Answer 40

- neck mass - dysphagia - hoarsenss - airway compromise - paraneoplastic syndrome

Question 41

treatment of medullary carcinoma

Answer 41

total thyroidectomy

Question 42

is anaplastic carcinoma dangerous/associated with death

Answer 42

yes