Thyroid

Question 0

Describe the development of the thyroid

Answer 0

It is formed near the foremen caecum in the tongue, it them migrates to its fully formed position near the oesophagus and the trachea, found below the thyroid cartilage.

Question 1

Name the function of the thyroid

Answer 1

The thyroid gland creates thyroid hormone (t3 and t4) which is involved in metabolism. Iodine taken from the blood and bound to a protein thyroglobulin. The production is controlled by a negative feedback loop including TRH from the para ventricular nuclei and TSH from the anterior pituitary. If there are high levels of thyroid hormone they act as a negative feedback there is a reduction in TRH and TSH.

Question 2

What disease can affect the thyroid gland

Answer 2

May be a problem with the development - thyroglossal cyst
Over or under active
Inflammatory or autoimmune conditions
Goitre
Benign or malignant neoplasia

Question 3

How would you manage someone with suspected thyroid disease?

Answer 3

1. Take a history - symptoms? Weight gain/loss
2. Examination - appearance, hands/eyes, lymphadenopathy
3. Provisional diagnosis
4. Relevant investigations according to the provisional diagnosis
5. Definitive diagnosis with the help of investigations
6. Management and treatment suitable for the diagnosis

Question 4

What would you look for in a thyroid examination?

Answer 4

Ask the patient to swallow, the thyroid is attached via a ligament to the trachea so they should move together.
Any lumps associated with the thyroid would roughly be in the midline
Thyroglossal cysts may be a developmental error

Question 5

What’s the difference between Goiter and Thyroid nodules?

Answer 5

A goiter is an enlargement of the gland itself resulting in pain and pressure symptoms of the trachea and the oesophagus. They are often visible to the naked eye.

Thyroid nodules are growths on the gland which may go unnoticed or be less symptomatic.

Question 6

Name the malignant tumours of the thyroid gland

Answer 6

1. Papillary - most common, 98% survival rate, 80% of tumours
2. Follicular - 2nd most common
3. Medullary - genetically inherited
4. Anaplastic - median survival is 38 days
5. Lymphoma
6. Secondary - metastasis from distant sites