Thyroid Pathology

Question 1

What vertebral level is the thyroid gland at?

Answer 1

C6-T1

Question 2

What lobe may or may not be present due to anatomical variation?

Answer 2

Pyramidal lobe

Question 3

What is the blood supply to the thyroid gland?

Answer 3

Superior and inferior thyroid arteries:
Superior = from external carotid
Inferior = from right subclavian

Question 4

What is the venous drainage of the thyroid gland?

Answer 4

Superior, middle and inferior thyroid veins:
Superior and middle = into internal jugular (then brachiocephalic)
Inferior = directly into brachiocephalic

Question 5

What hormones are secreted by the thyroid gland?

Answer 5

T3/4/Thyroxine (from follicular cells),

Calcitonin (from parafollicular cells)

Question 6

What substance is added to convert T3 - T4?

Answer 6

Iodine

Question 7

What is the role of thyroid hormones?

Answer 7

Increase metabolic rate, increase thermogenesis, required for growth and development

Question 8

How is most thyroxine transported in the blood?

Answer 8

Bound to thyroxine binding globulin

Question 9

What is the most biologically active form of thyroxine?

Answer 9

T3 (de-iodinated at cells by enzymes from T4-T3)

Question 10

What is the system of release of thyroxine (negative feedback)?

Answer 10

TRH (hypothalamus) -
TSH (pituitary) -
T3/4 (thyroid)

Question 11

What is the autoimmune cause of hypothyroidism?

Answer 11

Hashimotos

Question 12

What are the results of investigation of primary hypothyroidism?

Answer 12

Low fT3/4, high TSH (due to failure at thyroid gland)

Hashimoto’s: anti TPO antibodies

Question 13

What are the investigation results of secondary hypothyroidism?

Answer 13

Low fT3/4, low TSH (failure at pituitary or hypothalamus)

Question 14

What is goitrous hypothyroid due to?

Answer 14

Hashimoto’s thyroiditis (chronic)

Question 15

What is the cause of non-goitrous thyroiditis?

Answer 15

Atrophic

Question 16

How does hypothyroidism present?

Answer 16

Coarse sparse hair, more common in women, puffy eyes, cold intolerance, overweight, bradycardia, constipation

Question 17

How is hypothyroidism treated?

Answer 17

Levothyroxine

Question 18

What is a myxoedema coma?

Answer 18

Severe consequence of untreated hypothyroidism - medical emergency requiring intensive care

Question 19

What is the autoimmune cause of hyperthyroidism?

Answer 19

Graves disease

Question 20

What are the main causes of hyperthyroidism?

Answer 20

Autoimmune, toxic solitary nodule, toxic multi nodular goitre

Question 21

How does hyperthyroidism present?

Answer 21

Weight loss, heat intolerance, palpitations/AF, anxiety/nervousness, diarrhoea, muscle weakness, tremor/sweating

Question 22

What are the clinical signs of Graves disease?

Answer 22

Women, young, eye disease, pretibial myxoedema, thyroid bruits

Question 23

How is hyperthyroid diagnosed?

Answer 23

Raised fT3/4, decreased TSH

Graves: anti-TPO antibodies

Question 24

How is a nodular thyroid disease diagnosed?

Answer 24

High uptake or irregular scintigraphy (thyroid uptake) scan

Question 25

What is the first and second line treatment of hyperthyroidism?

Answer 25

Carbimazole | Propylthiouracil (PTU)

Question 26

What risk is associated with hyperthyroid treatment and how is this managed?

Answer 26

Agranulocytosis | If have severe sore throat and fever immediately stop medication and do FBC

Question 27

What are the types of differentiated thyroid cancer?

Answer 27

Papillary (most common) and follicular

Question 28

What is the prognosis of thyroid cancer?

Answer 28

Very good

Question 29

How does thyroid cancer present?

Answer 29

Asymptomatic, more common in women, palpable nodules

Question 30

How is thyroid cancer diagnosed?

Answer 30

Ultrasound guided FNA (fine needle aspiration) | NO thyroid isotope scan/CT/MRI

Question 31

How is a thyroglossal cyst identified and managed?

Answer 31

Moves with the tongue when you stick it out, usually benign so just reassure

Question 32

What is a thyroid storm?

Answer 32

Inadequately treated thyrotoxicosis - medical emergency