Clinical thyroid disease

Question 1

Symptoms of hypothyroidism

Answer 1

weight gain and lethargy 
cold intolerance 
constipation 
heavy periods 
dry skin/hair 
bradycardia
slow reflexes 
goitre 
severe = puffy face, large tongue, hoarseness, coma

Question 2

Symptoms of hyperthyroidism

Answer 2

weight loss 
heat intolerance 
bowel frequency 
light periods 
palpitations 
goitre 
thyroid eye symptoms 
hyperreflexia tremors

Question 3

What is the “odd” symptom out when it comes to hyper/hypo thyroidism?

Answer 3

menstruation

Question 4

List the TSH and FT3/4 for the 3 types of hypothyroidism

Answer 4

primary = TSH high, fT3/4 - low
secondary - both low
subclinical - TSH high, T3/4 - normal

Question 5

Epidemiology of hypothyroidism

Answer 5

most common endocrine condition after Type 1DM
more women effected than men
subclinical hypothyroidism common in older women
1 in 3500 births - congenital hypothyroidism

Question 6

Congenital causes of primary hypothyroidism

Answer 6

dyshormonogenesis

developmental eg agenesis

Question 7

Acquired causes of primary hypothyroidism

Answer 7

autoimmune eg Hashimoto’s
Iatrogenic eg radioiodine, post operative
chronic iodine deficiency
post sub acute thyroiditis eg postpartum thyroiditis

Question 8

Causes of secondary/tertiary hypothyroidism

Answer 8

pituitary tumour 
craniopharyngioma 
Isolated TRH deficiency 
post pituitary surgery 
Sheehan's syndrome

Question 9

Investigations for hypothyroidism

Answer 9

TSH/fT4 
autoantibodies - TPO
FBC 
muscle enzymes 
lipids 
hyperprolactinaemia 
hyponatraemia

Question 10

Most common treatment for hypothyroidism

Answer 10

levothyroxine - T4

Question 11

Levothyroxine treatment regimen

Answer 11

50 micrograms a day –> 100 micrograms after 2 weeks
annual TSH testing
half life is 7 days
increase dose until TSH is normal

Question 12

Other treatment methods for hypothyroidism

Answer 12

T3 tablets

mixture of T3/4 tablets

Question 13

Treating hypothyroidism in someone with IHD

Answer 13

treatments increase heart rate
lower dose and increase cautiously
can precipitate angina

Question 14

Treating hypothyroidism in pregnancy

Answer 14

Need more - higher levothyroxine dose

Question 15

When should treatment be considered in subclinical hypothyroidism?

Answer 15

TSH>10
TSH>5 with positive thyroid antibodies
TSH elevated with symptoms - trial therapy

Question 16

Risks of over treating (subclinical) hypothyroidism

Answer 16

AF

osteopenia

Question 17

Why is it important to treat hypothyroidism (subclinical included) before/during pregnancy?

Answer 17

More levothyroxine is required

reduce risk of foetal loss and lower IQ

Question 18

6 causes of goitre

Answer 18

physiological eg puberty/pregnancy 
autoimmune destruction eg graves/hashimotos 
iodine deficiency 
thyroiditis eg acute, chronic fibrotic 
dyshormonogenesis 
goitrogens

Question 19

5 types of goitre

Answer 19

multinodular 
diffuse eg colloid, simple 
cysts
tumours eg adenoma, carcinoma, lymphoma 
miscellaneous eg TB, sarcoidosis

Question 20

Risk factors for solitary thyroid nodule malignancy

Answer 20

child, under 30, over 60
head and neck irradiation
pain, cervical lymphadenopathy

Question 21

Investigations for solitary nodule thyroid

Answer 21

thyroid function test 
FNA 
isotope scanning if low TSH 
USS 
Chest and thoracic inlet x-rays

Question 22

2 types of differentiated thyroid cancer

Answer 22

papillary

follicular

Question 23

Papillary thyroid cancer

Answer 23

commonest, multifocal, local spread

excellent prognosis

Question 24

Follicular thyroid cancer

Answer 24

mets - lung, bone
usually single lesion
good prognosis if treatable

Question 25

Poor prognostic factors for thyroid cancer

Answer 25

spread out of capsule, under 16 and over 45, mets, TNM, tumour size

Question 26

Management of thyroid cancer

Answer 26

thyroidectomy high dose radioiodine long term suppressive thyroxine

Question 27

Follow up of thyroid cancer

Answer 27

thyroglobulin - tumour marker | whole body iodine scan followed by 2-4 weeks of thyroxine withdrawl

Question 28

3 other types of thyroid cancer

Answer 28

anaplastic lymphoma medullary

Question 29

Anaplastic thyroid cancer

Answer 29

rare, aggressive, locally invasive | poor prognosis - does not respond to radioiodine

Question 30

Medullary thyroid cancer

Answer 30

parafollicular c cells MEN 2 association serum calcitonin increased treat with total thyroidectomy and prognosis variable

Question 31

3 broad causes of thyrotoxicosis

Answer 31

primary secondary thyrotoxicosis without hyperthyroidism

Question 32

Primary causes of thyrotoxicosis

Answer 32

graves disease toxic multinodular goitre toxic adenoma

Question 33

Secondary causes of thyrotoxicosis

Answer 33

pituitary adenoma secreting TSH

Question 34

Causes of thyrotoxicosis without hyperthyroidism

Answer 34

excessive thyroxine administration | destructive thyroiditis

Question 35

Investigation of Graves disease

Answer 35

family history - autoimmune TSH receptor antibodies Thyroid peroxidase antibodies

Question 36

Diagnosis of graves disease

Answer 36

``` thyroid eye symptoms pretibial myxoedema clubbing gynaecomastia Hyperthyroidism Thyroid antibodies goitre ```

Question 37

What is multinodular goitre?

Answer 37

common cause of thyrotoxicosis in elderly no graves disease will spontaneously go into remission

Question 38

Explain subacute thyroiditis

Answer 38

younger patients with viral trigger eg enterovirus painful goitre, myalgia, fever ESR increased followed by period of hypothyroidism - months short term steroids and NSAIDs

Question 39

Management of hyperthyroidism

Answer 39

radioactive iodine anti-thyroid drugs thyroidectomy beta blockers - symptomatic

Question 40

What is the main anti-thyroid drug?

Answer 40

carbimazole

Question 41

Side effects of carbimazole

Answer 41

rash | agranulocytosis - neutropenia

Question 42

2 methods of carbimazole administration

Answer 42

block-replace | titration regimen

Question 43

Explain the titration regimen of carbimazole

Answer 43

start on high dose reduce until 5mg/day is reached most common method 50% cure, 30% hypothyroidism

Question 44

Explain the block-replace method for carbimazole

Answer 44

block with carbimazole replace with thyroxine higher side effects

Question 45

3 selected cases for long term low dose carbimazole

Answer 45

elderly cardiac problems unwilling for Radioactive iodine

Question 46

When is radioactive iodine not used?

Answer 46

pregnancy and young people | with severe eye disease

Question 47

2 methods of radioiodine administration

Answer 47

high dose ablative | variable calculated

Question 48

Is high dose ablative or variable calculated used more for radio iodine administration?

Answer 48

high dose ablative | high chance of becoming hypothyroid

Question 49

What is meant by subclinical hyperthyroidism? When should it be treated

Answer 49

TSH reduced but fT3/4 unaffected as of yet AF and osteopenia risk ATD/RAI if persistent and those at cardiac risk