Case 7 Thyroid

Question 1

Which hormones are released from the anterior pituitary?

Answer 1

FSH, LH, ACTH, TSH, Prolactin, Endorphins, Growth hormone

Question 2

Which hormones are released from the posterior pituitary?

Answer 2

ADH and oxytocin

Question 3

Which hormone is released from the intermediate lobe of the pituitary?

Answer 3

Melanocyte Stimulating Hormone

Question 4

Which hormones are released by the medulla of the adrenal gland?

Answer 4

Adrenaline and Noradrenaline

Question 5

What are the three layers of the cortex of the medulla and what do they each release?

Answer 5

Glomerulosa, Fasciculata, Reticularis

Mineralcorticoids, Glucocorticoids, Androgens

Question 6

What stimulates the release of TSH?

Answer 6

Anterior pituitary stimulation from TRH from hypothalamus

Question 7

What is most T3 and T4 bound to?

Answer 7

Thyroxine binding globulin

Question 8

What are the main functions of free T3 and T4?

Answer 8

Increase cell metabolism via cell receptors, growth and mental development, increase catechloamine effects

Question 9

Which conditions is TBG low in?

Answer 9

Nephrotic syndrome and malnutrition (protein loss), drugs (androgens, corticosteroids, phenytoin), chronic liver disease and acromegaly

Question 10

If hyperthyroid is suspected which TFTs should be performed?

Answer 10

TSH, T4 and T3

Question 11

What will be the results of most hyperthyroid TFTs?

Answer 11

Low TSH and raised T4

Rare cases of TSH secreting pituitary adenoma will lead to raised TSH

Question 12

When TSH, T4 and T3 levels are low what are the two possibilities? What should be done if these are the results?

Answer 12

Sick euthyroid or pituitary disease. Repeat after recovery from illness.

Question 13

In Graves’, which antibody is increased?

Answer 13

TSH receptor antibody

Question 14

Which autoantibodies are present in autoimmune thyroid disease?

Answer 14

Antithyroid peroxidase or antithyroglobulin antibodies may be elevated in Hashimoto’s or Graves’

Question 15

Which test is used for monitoring carcinoma treatment and has low levels in factitious hyperthyroid?

Answer 15

Serum thyroglobulin

Question 16

What is factitious hyperthyroidism?

Answer 16

Elevated thyroid hormone from taking too much thyroid medicine, accidentally or on purpose

Question 17

What is the use of an ultrasound scan re thyroid?

Answer 17

Distinguishing cystic (usually benign) nodule from solid (possibly malignant) nodules. If a solitary or dominant nodule is present in a multi-nodular goitre, perform fine needle aspiration

Question 18

What is an isotope scan useful for?

Answer 18

Hyperthyroid causes, detecting retrosternal goitre, ectopic thyroid tissue or thyroid metastases

Question 19

When is surgery needed for suspicious nodules?

Answer 19

Rapid growth, compression signs, dominant nodule on scintigraphy, nodule larger than 3cm, hypo-echogenicity

Question 20

What is thyrotoxicosis?

Answer 20

Clinical effect of excess thyroid hormone

Question 21

What are the main symptoms of thyrotoxicosis (think increased metabolic rate)? (Rare ones?)

Answer 21

Diarrhoea, decreased weight with increased appetite, sweats, heat intolerance, palpitations, overactive tremor, irritability, labile emotions, oligomenhorrea
Rare: psychosis, chorea, panic, itch, alopecia, urticaria

Question 22

What are the signs of thyrotoxicosis on examination?

Answer 22

Bradycardia, AF or SVT, warm moist skin, fine tremor, palmar erythema, thin hair, lid lag, lid retraction, goitre, thyroid nodules or bruit

Question 23

What are the signs of Graves’ disease?

Answer 23

Eye disease (exopthalamos, opthalmoplegia)
Pretibial myoedema
Thyroid acropachy in extreme circumstances

Question 24

What tests indicate thyrotoxicosis?

Answer 24

Low TSH with elevated T4 and T3
Perhaps mild normocytic anaemia
Mild neutropenia in Graves
Elevated ESR, Ca and LFT

Question 25

What other tests should be performed for thyrotoxicosis?

Answer 25

Thyroid autoantibodies, isotope scans and eye tests

Question 26

What is the main cause of thyrotoxicosis?

Answer 26

Graves disease