5.14 Thyroid disorders (tutorial)- wishy washy

Question 1

A 30 year old woman attends clinic and presents you with a letter from a private health clinic. She has been experiencing palpitations. The letter contains the following results:

fT4 30 pmol/L (9 - 23)
fT3 11 pmol/L (3.1 – 6.8)
TSH <0.01 mU/L (0.3 – 4.2)

What is the diagnosis? What are the possible causes of this?

Answer 1

fT4, fT3 are both high
TSH is low
Primary hyperthyroidism
Can be due to autoimmunity

Question 2

What clues from the history and examination could help you work out which cause is most likely?

Answer 2

Issue with the thyroid gland itself as TSH is low, but thyroid hormones are high.
Autoimmune? Grave’s disease?

Question 3

The patient gives you a more detailed history. She has recently noticed herself to be more ‘snappy’ at work, leading to a few workplace arguments. She hadn’t been feeling herself for a while and was upset about this and had a private health screening through work. On direct questioning, she admitted to an 18 month history of palpitations, weight loss and sweating. Two aunts had neck operations and she had noticed a swelling in her own neck over the past year.

On examination she had a fine tremor and looked thin. Her pulse was 112 beats per minute and her blood pressure 106 / 70 mmHg. Examining her neck, there was a mass in the centre of her neck, which was soft, extended symmetrically either side of the midline and was not tender to touch. This mass moved with swallowing. She had bilateral exophthalmos (prominent eyes).

Now you know more, what is the likely diagnosis based on the history and examination? Explain why.

Answer 3

Grave’s disease- symmetrical goitre, exophthalmos, 2 aunts had neck operations, goitre is soft (would be more firm in thyroiditis or toxic nodular thyroid disease)

Question 4

What investigation will confirm the cause of her hyperthyroidism?

Answer 4

Measure TSH-receptor antibodies

Question 5

What treatment should she receive in the short term? What are the long term treatment options?

Answer 5

Short term: non-specific beta blockers for symptoms

Long term: thionamides e.g. carbimazole to treat hyperthyroidism, radioiodide, surgery (thyroidectomy)