Thyroid Cancer

Question 1

what are the 5 histological classes of thyroid cancer?

Answer 1

• papillary
• follicular
• medullary
• anaplastic
• other

Question 2

what are the 2 most common types of thyroid cancer?

Answer 2

papillary

follicular

Question 3

what does a medullary thyroid cancer secrete?

Answer 3

calcitonin

Question 4

what is the prognosis like of anapaestic thyroid cancer?

Answer 4

very poor

almost anyone who gets it dies within a few months

Question 5

what does the term differentiated thyroid cancer refer to?

Answer 5

papillary & follicular variants

Question 6

what does the term differentiated refer to?

Answer 6

histological appearance but also to physiological characteristics that allow diagnosis & treatment

Question 7

what do most DTCs take up?

Answer 7

iodine

Question 8

what do most DTCs secrete?

Answer 8

thyroglobulin

Question 9

what are DTCs driven by?

Answer 9

TSH

Question 10

is thyroid cancer common or not?

Answer 10

not common at all

Question 11

does DTC have higher or lower incidence in afro-americans?

Answer 11

lower

Question 12

what does DTC have a strong association with?

Answer 12

radiation e.g. treatment for lymphoma

Question 13

how do the majority of DTCs present?

Answer 13

palpable nodules

Question 14

what is the commonest histological type of thyroid cancer?

Answer 14

papillary

Question 15

how does papillary thyroid cancer commonly spread?

Answer 15

via lymphatics

Question 16

where would a haematogenous spread likely go?

Answer 16

lungs
bone
liver
brain

Question 17

which thyroiditis is papillary thyroid cancer associated with?

Answer 17

hashimoto’s thyroiditis

Question 18

what is the second commonest type of DTC?

Answer 18

follicular carcinoma

Question 19

in which regions is the incidence of follicular carcinoma slightly more common?

Answer 19

regions of relative iodine deficiency

Question 20

follicular carcinoma is spreads more commonly through which system?

Answer 20

haematogenously

Question 21

in which type of DTC are you more likely to find lymph node enlargement?

Answer 21

papillary

Question 22

what is the most common 1st line investigation for suspected thyroid cancer?

Answer 22

ultrasound guided FNA of the lesion

Question 23

FNA

Answer 23

fine needle aspiration

Question 24

what is the 2nd most common investigation of thyroid cancer?

Answer 24

excision biopsy of lymph node

Question 25

what investigation should a patient be sent for pre-operatively if vocal cord palsy is suspected clinical?

Answer 25

pre-operative laryngoscopy

Question 26

what are the surgical options for thyroid cancer treatment?

Answer 26

thyroid lobectomy with isthmusectomy sub-total thyroidectomy total thyroidectomy

Question 27

how is surgical risk assessed?

Answer 27

``` AMES Age Metastases Extent of primary tumour Size of primary tumour ```

Question 28

what is the most common complication of thyroid surgery & why?

Answer 28

hypocalcaemia due to inadvertent removal of all parathyroid glands

Question 29

in which patients is whole body iodine scanning used in?

Answer 29

patients who have undergone sub-total or total thyroidectomy

Question 30

how long after an operation is whole body iodine scanning usually performed?

Answer 30

3-6 months

Question 31

for how long before the whole body iodine scan is T4 stopped?

Answer 31

4 weeks prior

Question 32

for how long before the whole body iodine scan is T3 stopped?

Answer 32

2 weeks prior

Question 33

what level should TSH be at for whole body iodine scanning to be effective?

Answer 33

greater than 20

Question 34

rhTSH

Answer 34

genetically made TSH aka thyrogen

Question 35

what is the benefit of hTSH injections?

Answer 35

gives short rise in TSH levels without stopping thyroxin, no change in symptoms

Question 36

where is iodine normal taken up in the body?

Answer 36

salivary glands stomach bladder (excreted via kidney)

Question 37

TRA

Answer 37

thyroid remnant ablation

Question 38

when is TRA used?

Answer 38

in those with residual disease

Question 39

which protein can be used as a thyroid tumour marker after TRA?

Answer 39

thyroglobulin

Question 40

which cells produce thyroglobulin?

Answer 40

normal thyroid cells | DTC cells

Question 41

what should the serum thyroglobulin level be in a patient who is cured of DTC?

Answer 41

undetectable

Question 42

why would you do TRA?

Answer 42

to ablate residual thyroid tissue in order to destroy occult microfoci

Question 43

what are patient's biochemical picture like after TRA?

Answer 43

hyperthyroid

Question 44

at what level does hyperthyroidism after TRA become risky?

Answer 44

30+

Question 45

what does hyperthyroidism of 30+ increase the risk of?

Answer 45

osteoporosis & AF

Question 46

what is the absolute contraindication to TRA?

Answer 46

pregnancy