Thyroid cancer

Question 1

The most common T cancer?

Answer 1

Papillary 80%
Follicular 20%

Question 2

Presentation of T cancer?

Answer 2

Present with palpable nodules
small chance to find iy on histological section (in the lab)
5% we find cancer somewhere else

Question 3

Papillary T cancer

Question 4

Follicular carcinoma

Answer 4

• Second commonest histological type
• Incidence slightly higher in regions of relative iodine deficiency
• Tend to spread haematogenously
• Lymphatic spread and therefore lymph node enlargement relatively rare.
• Prognosis similar to that of papillary cancer

Question 5

Investigation of T cancer?

Answer 5

• US and usung the classifications with FNA guides
• excision biopsy of lymph nodes
• No need to istopic thyroid scan
• No need to do CT/MRI
• If vocal cord palsy suspected clinically, for pre-operative laryngoscopy

Question 6

Clinical predictors of malignancy?

Answer 6

New thyroid nodule age <20 or >50
Nodule increasing in size
Male is worrying
lesion> 4cm
Hx of head and neck irradiation
Vocal cord palsy

Question 7

Operative Mx?

Answer 7

• Surgery is treatment of choice
• T lobectomy with isthmusectomy
• Sub-total thyroidectomy
• Total ^^

Question 8

Risk Stratification post-op?

Answer 8

AMES
used to stratify patients as low or high risk

Question 9

AMES low risk?

Answer 9

Younger patients ( men <40, women <50) with no evidence of metastases
Older patients with intrathyroidal papillary lesion or minimally invasive follicular lesion and primary tumour < 5cm and no distant metastases
20 year survival for AMES low risk group is claimed to be 99%

Question 10

AMES high risk?

Answer 10

All patients with distant metastases
Extrathyroidal disease in patients with papillary cancer
Significant capsular invasion with follicular carcinoma
Primary tumour > 5cm in older patients
20 year survival in AMES high risk is 61%

Question 11

Whole body iodine scanning?

Answer 11

Used in patients who have undergone sub-total or total thyroidectomy
Usually performed 3-6 months post-op
T4 stopped 4 weeks prior to scan
T3 stopped 2 weeks prior to scan
rhTSH (Give to stimulate the TSH to drive the cancer cells to observe the iodine) is far better as no need to stop T3/T4
TSH should be greater than 20 for best results
Sensitivity determined by ensuring that TSH is elevated
rhTSH injections Monday/Tuesday
2-4 mCi (75-150 MBq) I-131 administered as capsule on Wednesday
Patient returns for imaging on Friday
Results of scan inform treatment decision

Question 12

Thyroid Remnant Ablation?