Endocrinology 4 - Thyroid Function Tests

Question 1

describe hormone results in hyperthyroidism

Answer 1

TSH low, T3,4 high

*there is one exception where both will be high!

Question 2

what will the hormone results be with a pituitary adenoma

Answer 2

hyperthyroid

high TSH, high T3,4

Question 3

hypothyroidism hormone levels

Answer 3

low T3,4, high TSH

*with one exception!

Question 4

what will the hormone results be with a pituitary/hypothalamic cause of hypothyroidism?

Answer 4

low TSH, low T3,4

Question 5

list the 3 main antibodies involved with thyroid pathology

Answer 5

anti-TPO - Hashimoto’s thyroiditis, can be present in Grave’s too

anti-thyroglobulin - may be present in H+G, but notably in thyroid cancers (can also be incidental)

TSH receptor antibodies - Grave’s

Question 6

what use is ultrasound with thyroid pathology?

Answer 6

determines cystic vs solid nodules

Question 7

explain the 3 patterns of radioisotope thyroid uptake:

• diffuse high x1
• focal x2
• cold areas x1

Answer 7

diffuse high = Grave’s
focal high uptake = toxic multinodular goitre or adenomas
cold areas = thyroid cancer