thyroid cancer

Question 1

4 types of thyroid cancers

Answer 1

• papillary
• follicular
• medullary
• anaplastic

Question 2

what types are differentiated

Answer 2

papillary and follicular

Question 3

what drives differentiated cancers

Answer 3

DTC and TSH

Question 4

presentation of thyroid cancer

Answer 4

palpable nodules mainly

Question 5

how does papillary cancer spread

Answer 5

through lymphatics or haematogenous

Question 6

what disease is papillary thyroid cancer associated with

Answer 6

hashimoto’s thyroiditis

Question 7

how does follicular carcinoma tend to spread

Answer 7

haematogenously

Question 8

investigation for thyroid cancer

Answer 8

• ultrasound guided FNA of the lesion

- excision biopsy of lymph node

Question 9

clinical predictors of malignancy

Answer 9

• new thyroid nodule <20 or >50
• male
• nodule size increasing
• lesion >4cm in diameter
• history of head and neck irradiation
• vocal cord palsy

Question 10

management for thyroid cancer

Answer 10

• thyroid lobectomy with isthmusectomy
• sub-total thyroidectomy
• total thyroidectomy
• TRA

Question 11

risk stratification post-op

Answer 11

AMES

Age
Metastases
Extent of primary tumour
Size of primary tumour

Question 12

what older patients are low risk

Answer 12

ones with:

• intrathyroidal papillary lesion
• minimally invasive follicular lesion
• primary tumour < 5cm
• no distant metastases

Question 13

what patients are AMES high risk

Answer 13

• distant metastases
• extrathyroidal disease in papillary
• significant capsular invasion with follicular
• primary tumour >5cm in older patients

Question 14

who gets thyroid lobectomy with isthmusectomy

Answer 14

• Papillary microcarcinoma ( < 1cm diameter)
• Minimally invasive follicular carcinoma with capsular invasion only
• Patients in AMES low risk group

Question 15

who gets sub-total or total thyroidectomy

Answer 15

• DTC with extra-thyroidal spread
• Bilateral / multifocal DTC
• DTC with distant metastases
• DTC with nodal involvement
• Patients in AMES high risk group

Question 16

post operative care

Answer 16

• calcium checked within 24 hours
• calcium replacement if falls below 2mmol/L
• IV calcium if below 1.8 mmol/L
• patient discharged on T3 or T4

Question 17

who gets whole body iodine scanning

Answer 17

patients who have undergone sub-total or total thyroidectomy

Question 18

when is T4 and T3 stopped before whole body iodine scan

Answer 18

• T4 stopped 4 weeks prior

- T3 stopped 2 weeks prior

Question 19

what happens in thyroid remnant ablation

Answer 19

• admitted to lead lined room
• pre-treated with rhTSH
• 2 or 3 GBq capsule of I-131 administered
• patient uses disposable cutlery etc

Question 20

when are patients discharged from remnant ablation

Answer 20

when count rate <500cps at 1m

Question 21

post TRA treatment

Answer 21

• patients maintained on T4

- aim to suppress TSH to <0.1 U/l and FT4 below 25

Question 22

what does TRA do

Answer 22

• Ablate residual thyroid tissue in order to destroy occult microfoci
• Remove residual thyroid tissue which may be a source of Tg and therefore confound the levels during follow-up
• Permit predictively useful scanning in whole body scans and subsequent high dose therapy if required