Differentiated thyroid cancer

Question 1

What are the histological classifications of thyroid cancer?

Answer 1

Papillary
Follicular
Medullary
Anaplastic

Question 2

What do most differentiated thyroid cancers take up, secrete and are driven by?

Answer 2

Take up iodine
Secrete thyroglobulin
Driven by TSH

Question 3

How do differentiated thyroid cancers present?

Answer 3

Palpable nodule

5% present with a local or disseminated met

Question 4

Where will papillary thyroid cancer spread?

Answer 4

Via lymph to lungs, bone, liver and brain

Question 5

What autoimmune disease is papillary thyroid cancer associated with?

Answer 5

Hashimotos

Question 6

Where is the incidence of follicular carcinoma higher?

Answer 6

Regions of relative iodine deficiency

Question 7

How are thyroid carcinomas investigated?

Answer 7

Ultrasound guided FNA
Excision biopsy of lymph node
If vocal cord palsy, do pre-op laryngoscopy

Question 8

What are the clinical predictors of malignancy?

Answer 8

New thyroid nodule age 
Male
Nodule increasing in size
Lesion over 4 cm in diameter
History of head and neck irradiation 
Vocal cord palsy

Question 9

How are thyroid cancers treated?

Answer 9

Surgery treatment of choice - thyroid lobectomy with isthmusectomy
Sub-total thyroidectomy
Total thyroidectomy

Question 10

What risk stratification is used post op?

Answer 10

AMES
Age
Mets
Extent of tumour
Size of tumour

Question 11

Who is AMES low risk?

Answer 11

Younger patients (women <50, men <40) with no evidence of mets 
Older patients with intathyroid papillary lesion with no distant mets

Question 12

What are the 20 year survival for AMES low risk?

Answer 12

99%

Question 13

Who are AMES high risk?

Answer 13

Distant mets
Extra Thyroid disease in those with papillary cancer
Significant capsular invasion with follicular cancer
Primary tumour over 5cm

Question 14

What is the 20 year survival in AMES high risk?

Answer 14

61%

Question 15

When is a thyroid lobectomy with isthmusectomy used?

Answer 15

Papillary microcarcinoma (<1cm)
Minimally invasive follicular with capsular invasion only
AMES low risk

Question 16

When is a sub-total or total thyroidectomy used?

Answer 16

DTC with extra-thyroid spread
Bilateral or multifocal DTC
Distant mets
Nodal involvement
AMES high risk

Question 17

What is the post op care after thyroid surgery?

Answer 17

Calcium check within 24 hours
Calcium replacement if calcium falls below 2 mmol/l
IV calcium for levels below 1.8 mmol/l or if symptomatic
Discharged on T3 or T4

Question 18

When is whole body iodine scanning used?

Answer 18

Undergone sub-total or total thyriodectomy

3-6mnths post op

Question 19

What is the pharma regime before a whole body iodine scan?

Answer 19

T4 stopped 4 weeks prior
T3 stopped 2 weeks prior
TSH greater than 20

Question 20

What is thyroid remnant ablation?

Answer 20

Radiation aimed at thyroid

Ablate residual thyroid tissue in order to destroy occult microfoci

Question 21

What can be used as a tumour marker?

Answer 21

Thyroglobulin