1. Thyroid: Clinical Cases
Dr Sunil Zachariah
Consultant Endocrinologist
Surrey and Sussex NHS Trust
& Spire Gatwick Park Hospital

2. Thyroid is the only source of T4
Thyroid secretes 20% of T3, remainder is generated in extra glandular tissues by conversion of T4 to T3

3. Normal range
FT pmol/l
fT pmol/l
TSH mu/L

4. Case 1
Female aged 40 years
Palpitations, weight loss and mild proptosis
Smallish smooth goitre
FT4 80
TSH<0.01

6. Graves Disease TSH receptor antibodies Carbimazole Propylthiouracil
Treatment schedule
?Block and replace
Permanent cure

7. Case 2 Female aged 76 years Gradual weight loss
Solitary thyroid nodule
FT4 32
TSH<0.01

9. Management toxic Nodule
Radioactive iodine
?FNA first if palpable nodule as low risk of malignancy in toxic nodule

10. Case 3 60 year old female 6 weeks post radioiodine treatment FT4 11
TSH 0.02

11. Post radioiodine thyroid function
Check 6 weeks after treatment
TFTs may fluctuate
50% risk of hypothyroidism

12. Case 4
Female aged 79 years with fast AF
FT4 19.5
TSH 0.2

13. This case probably not for antithyroid treatment
If overtly hyperthyroid treat
Subclinical hyperthyroidism: Normal FT4, Low TSH
Risk factor for Atrial fibrillation, osteoporosis

14. Case 5 50 year old man Ventricular tachycardia with poor LV function
Controlled on Amiodarone
FT4 50
FT3 7
TSH<0.01

15. Amiodarone and Thyroid
Inhibits thyroidal iodide uptake
Inhibits conversion of T4 to T3 intracellularly
Inhibits T4 entry into cells
Direct T3 antagonism at level of cardiac tissue

16. What does it do to TFTs?
Early[1-10 days]: TSH increase, FT3 decrease, then Ft4 increase after 4 days
Later[1-4 months]: Ft4 increase by 40%, FT3 remains low or normal, TSH levels normalise
Long term: TSH may suppress

17. Amiodarone induced hyperthyroidism
2-12%
Type 1: Iodine overload in abnormal gland, treat with carbimazole or lithium
Type 2: Glandular damage, release of preformed hormones, treat with prednisolone mg/kg for 3-6 weeks
Management of tachyarrhythmia's: beta blockers if not in CCF
?total thyroidectomy (not radioiodine)

18. Case 6 30 year old female Recent flu tender enlargement thyroid FT4 28
TSH<0.01

19. De Quervains thyroiditis
Recheck TFTs-probably hypothyroid by then
Thyroid antibodies and ESR
Thyroid scintigram-reduced uptake
Symptomatic treatment with NSAIDs
Warn the possibility of recurrence

20. Case 7 Female age 25 years Hyperpyrexia ITU admission
Profound muscle weakness requiring ventilation
FT4 210
TSH<0.01

21. Thyrotoxic crisis Carbimazole 60-100 mg via NG tube
Propranolol infusion
Profound myopathy and even neuropathy can be associated with Grave’s

22. Case 8 65 year old male Pre coronary artery bypass surgery
Routine blood tests
FT4 3 mU/L
TSH 40 pmol/L

23. Management hypothyroidism with Coronary artery disease
May need to put in stents to allow introduction of triodothyronine and then thyroxine
Some patients symptomatic when thyroxine started/increased

24. Case 9
Female aged 32 years
Weight gain and thyroid
FT4 13
TSH 5.5

25. Sub clinical hypothyroidism
TSH>10
Antibody positive
Family history
Symptomatic
Monitor TFT 6 monthly

26. Case 10
Hypothyroid on replacement thyroxine 300 mcg
FT4 23
TSH 15

27. Hypothyroidism requiring high dose replacement
Check tablets each visit-check compliance
Check for malabsorption but unlikely
Probably continue to see but at infrequent intervals

28. Case 11
Female aged 60 years
Found collapsed at home
History of epilepsy
TFT checked in Causality
FT4 8.5
TSH 4.0

29. Low FT4, normal TSH Sick euthyroid
Possibly hypopituitary-cortisol/FSH/LH
Check medication-can be secondary to carbamazepine

30. Sick Euthyroid syndrome
Non thyroidal illness syndrome
Low FT4 and T3
Inappropriately normal/suppressed TSH
Context: Starvation, ITU, severe infections, renal failure, cardiac failure, malignancy

31. Case 13
Female aged 34 years
Secondary amenorrhoea
Low TSH
Low FT4

33. Hypopituitarism FSH/LH/Prolactin/cortisol
MRI Pitutary; ?empty fossa ?large adenoma
Start hydrocortisone first if needed, before thyroxine replacement

34. Case 14 22 year old female Admitted with hyper emesis gravidarum
Pulse 110 bpm
FT4 29
TSH<0.01

35. Management
Usually HCG induced in which case it will resolve spontaneously by around 14 weeks
If positive thyroid antibodies or history of grave’s disease then treat with PTU

36. Case 14 A] Palpitations, 10 weeks post partum Ft4 32 TSH 0.2
B] Tired, 10 weeks post partum
FT4 9
TSH 8

37. POSTPARTUM THYROIDITIS
Incidence varies from 5-11%
More common in women with a family history of hypothyroidism and positive TPO antibodies

38. Presentation is usually 3-4 months postpartum
CLINICAL FEATURES
Presentation is usually 3-4 months postpartum
Can be hypothyroidism (40%), hyperthyroidism (40%) or biphasic(20%)
Goiter is present in 50% of patients

39. Pathogenesis
Destructive autoimmune thyroiditis causing first release of thyroxine and then hypothyroidism as the thyroid reserve is depleted
FNAC shows lymphocytic thyroiditis

40. Diagnosis
Advise routine TFT in females who have positive TPO antibodies and type 1 diabetes
To distinguish from Graves disease use thyroid isotope scan and TSH receptor Ab

41. Management
Most patients recover spontaneously without requiring treatment
If hyperthyroid use beta blockers rather than antithyroid drugs as the problem is increased release, not synthesis
Hypothyroid phase is more likely to require treatment
Only 3-4% remain permanently hypothyroid
10-25% will recur in future pregnancies

42. Case 15
Female aged 30 years
New Thyroid enlargement

43. New Thyroid swelling FNAC if nodule size>1 cm
Repeat FNAC in 6 months
Impossible to differentiate between benign and malignant follicular neoplasm using FNAC

44. Case 16
Long standing goitre
FT4 28
TSH 7

45. Measurable TSH with raised FT4
Heterophile antibodies
TSH resistance syndromes
TSH oma-very rare

46. Thyroid hormone resistance
Syndrome characterized by reduced responsiveness to elevated circulating FT4 and FT3, non suppressed TSH
Short stature, hyperactivity, attention deficit
Differential diagnosis includes TSH secreting pituitary tumour

47. Case 17 27 year old female Follicular Cancer of Thyroid
Post surgery, post radioiodine ablation
On Thyroxine replacement (175 mcg)
FT4 19.8
TSH 0.05

48. Follow up of thyroid Cancer
Original diagnosis and treatment
If total thyroidectomy and ablative radioiodine, thyroglobulins usually undetectable if TSH unrecordable
Maintain TSH<0.05