Thyroid disorders

Question 1

Define hyperthyroidism

Answer 1

Overactivity of the thyroid gland resulting in excess thyroid hormone

Question 2

Causes of hyperthyroidism (6)

Answer 2

1. Grave’s disease (most common)
2. Toxic multinodular goitre
3. Toxic thyroid adenoma
4. Pituitary adenoma -> more TSH, high T3/T4
5. De Quervain’s thyroiditis
6. Drug induced

Question 3

Hyperthyroidism RF (5)

Answer 3

1. Female
2. Family history/genetic (HLA-DR3/4)
3. Stress
4. Smoking
5. Amiodarone

Question 4

Pathology of Graves’ disease

Answer 4

• Serum IgG antibodies called TSH receptor stimulating antibodies (TRAb) bind to TSH receptors on thyroid and stimulate T3/4 production
• Excess secretion, follicular hyperplasia, hyperthyroidism and goitre

Question 5

Specific symptoms of Graves’ disease (4)

Answer 5

1. Graves’ ophthalmology (extraocular muscle swellings - protruding eyes, lacrimation,, eye discomfort, diplopia)
2. Pretibial myxoedema (raised purple/red symmetrical skin lesions over anterolateral aspect of the shins)
3. Thyroid acropachy (finger clubbing, periosteal new bone formation)
4. Goitre

Question 6

Symptoms of hyperthyroidism (9)

Answer 6

1. Weight loss
2. Heat intolerance
3. Irritability
4. Sweating
5. Insomnia
6. Diarrhoea
7. Palpitations
8. Anxiety
9. Menstrual disturbance

Question 7

Signs of hyperthyroidism (9)

Answer 7

1. Tachycardia/AF
2. Tremor
3. Goitre
4. Hyperkinesia
5. Lid lag
6. Lid retraction
7. Thin hair and hair loss
8. Onycholysis - painless separation of the nail from nail bed
9. Exophthalmos - bulging of eye

Question 8

Investigations for hyperthyroidism (4)

Answer 8

1. TFTs - primary = low TSH, high T3/T4, secondary = high TSH/T3/4
2. Thyroid autoantibodies - thyroglobulin antibodies, TRAb, thyroid peroxidase antibodies (more in hypo)
3. Thyroid ultrasound
4. Radioactive iodine isotope uptake - high in Graves’

Question 9

Treatment of hyperthyroidism (4)

Answer 9

1. Beta blockers - reduces SNS activation
2. Carbimazole - blocks thyroid hormone synthesis and is immunosuppressant
3. Radioiodine therapy - iodine taken up and local irradiation and tissue damage
4. Thyroidectomy - thyroid replacement needed

Question 10

Complications of thyroidectomy (7)

Answer 10

1. Bleeding
2. Post-op infection
3. Hypocalcaemia
4. Hypothyroidism
5. Hypoparathyroidism
6. Recurrent laryngeal palsy - laceration
7. Recurrent hyperthyroidism

Question 11

Complications of hyperthyroidism

Answer 11

1. Congestive HF
2. AF
3. Osteoporosis
4. Graves’ ophthalmology complications
5. Graves’ dermopathy - elephantitis

Question 12

Thyroid crisis/storm

Answer 12

Rapid deterioration of thyrotoxicosis with

1. Hyperpyrexia
2. Tachycardia
3. Restlesslessness
4. Delirium, coma, death

Question 13

What is thyroid crisis precipitated by?

Answer 13

1. Infection
2. Stress
3. Surgery
4. Radioactive iodine therapy

Question 14

Treatment of thyroid crisis

Answer 14

1. Large dose carbimazole
2. Propranolol
3. Potassium iodide - acutely block thyroid hormone release from gland
4. Hydrocortisone - inhibit peripheral conversion of T4 to T3

Question 15

Define hypothyroidism

Answer 15

Underactivity of the thyroid gland. Affects women more than men.

Question 16

Causes of hypothyroidism (5)

Answer 16

1. Post-partum thyroiditis
2. Autoimmune thyroiditis
3. Iodine deficiency
4. Iatrogenic
5. Congenital hypothyroidism

Question 17

Drugs inducing hypothyroidism

Answer 17

1. Carbimazole
2. Lithium
3. Amiodarone
4. Interferon

Question 18

Drugs inducing hyperthyroidism

Answer 18

1. Iodine
2. Amiodarone
3. Lithium

Question 19

Signs of hypothyroidism : BRADYCARDIC

Answer 19

Bradycardia
Reflexes relax slowly
Ataxia
Dry thin hair/skin
Yawning/drowsy/coma
Cold hands (+low temp)
Ascites (+non pitting oedema + pericardial/pleural effusion)
Round puffy face
Defeated demeanour
Immobile
CCF

Question 20

Symptoms of hypothyroidism (10)

Answer 20

1. Weight gain
2. Hoarse voice
3. Goitre
4. Cold intolerance
5. Menorrhagia
6. Constipation
7. Lethargy/tiredness
8. Poor memory
9. Puffy eyes
10. Arthralgia/myalgia

Question 21

Diagnosis of hypothyroidism

Answer 21

1. High TSH, low T4
2. Low TSH and T4 - rare pituitary fault
3. High cholesterol and triglyceride, macrocytosis
4. Normochromic anaemia (less common)

Question 22

Causes of primary hypothyroidism

Answer 22

1. Primary atrophic hypothyroidism - lymphatic infiltration, atrophy, no goitre
2. Hashimoto’s thyroiditis - lymphocytic and plasma cell infiltration, goitre, more common in women 60-70
3. Iodine deficiency
4. Thyroidectomy or radioiodine treatment
5. Drug-induced
6. Subacute thyroiditis

Question 23

Treatment of hypothyroidism

Answer 23

1. Healthy and young - levothyroxine 0-100mcg/24h, review 12wks
2. Elderly or ischaemic heart disease - 25mcg/24h

Aim to get TSH >0.5

Question 24

Types of thyroid cancer (good-> bad prognosis)

Answer 24

1. Papillary
2. Follicular
3. Medullary cell
4. Lymphoma
5. Anaplastic

Question 25

Symptoms of thyroid cancer

Answer 25

1. Thyroid nodules 2. Dysphagia 3. Hoarseness of voice

Question 26

Signs of thyroid cancer

Answer 26

1. Lymph node metastases 2. Bone or lung metastases (rare) 3. Thyroid nodule with history of progressive increase in size 4. Hard and irregular nodule 5. Enlarged lymph nodes

Question 27

Investigations for thyroid cancer

Answer 27

1. Fine needle aspiration cytology biopsy 2. Thyroid ultrasound 3. TFTs - hyper/hypothyroidism must be treated before surgery

Question 28

Treatment for thyroid cancer

Answer 28

1. Papillary and follicular - total thyroidectomy with neck dissection, ablative radioiodine 2. Anaplastic and lymphoma - external radiotherapy, mainly palliative