thyroid 2

Question 1

hypothyroidism

Answer 1

insufficient thyroid hormone

Question 2

hypothyroidism in early childhood usually caused by

Answer 2

endemic environmental or dietary iodine deficiency

more rarely caused by inborn errors of metabolism

Question 3

effects on hypothyroidism in early childhood

Answer 3

short stature, coarse facial features, protruding tongue, umbilical hernia, severe mental impairment
T3 and T4 can cross placenta, so maternal thyroid deficiency before the fatal thyroid develops causes more severe problems

Question 4

fetal thyroid develops at

Answer 4

weeks 12-16, before this T3 and T4 can cross the placenta

if material thyroid deficiency, problems are severe

Question 5

hypothyroidism in adults

Answer 5

can be less severe, often subclinical
10x more common in women than men - mainly due to autoimmune thyroiditis
more common in >60 years
may result from defect anywhere in the hypothalamic, pituitary, thyroid axis

Question 6

chronic hypothyroidism leads to

Answer 6

myxedema

Question 7

hypothyroidism symptoms

Answer 7

• slowing of physical and mental activity
• cold intolerance
• overweight
• mimics depression
• decreased sympathetic activity, reduced sweating, decreased cutaneous blood flow
• decreased cardiac output, decreased exercise capacity, increased LDL thus increased atherosclerosis

Question 8

pathology of hypothyroidism in adults

Answer 8

decreased T4
increased TSH - loss of normal feedback inhibition
TSH is not raised if they hypothyroidism is secondary to hypothalamic or pituitary disease

Question 9

acute hypothyroidism

Answer 9

myxoedema crisis/come

acute illness is someone who is a hypothyroid patient

Question 10

Hashimoto’s thyroiditis

Answer 10

autoimmune disease - breakdown of self tolerance to thyroid antigens
occurs in any age including children
tends to run in families
usually hypothyroid but may be euthyroid or hyperthyroid

Question 11

hashimotos thyroiditis more common in men or women

Answer 11

women

Question 12

hashimotos sometimes overlaps with

Answer 12

other autoimmune disease of the thyroid - graves

other endocrine organs - pit adenoma, adrenal disease

Question 13

pathological findings in hashimotos

Answer 13

• diffuse lymphoid and plasma cell infiltrate with reactive lymphoid follicles
• degeneration and apoptosis of epithelial cells with oncocytic change - hurthle cells
• gland normal size or slightly small
• later atrophy, fibrosis (minority of patients)
• slightly increased risk of lymphoma and very slightly increased risk of carcinoma

Question 14

hashimotos brings increased risk of

Answer 14

lymphoma and carcinoma