thyroid cancer Flashcards
4 types of thyroid cancers
- papillary
- follicular
- medullary
- anaplastic
what types are differentiated
papillary and follicular
what drives differentiated cancers
DTC and TSH
presentation of thyroid cancer
palpable nodules mainly
how does papillary cancer spread
through lymphatics or haematogenous
what disease is papillary thyroid cancer associated with
hashimoto’s thyroiditis
how does follicular carcinoma tend to spread
haematogenously
investigation for thyroid cancer
- ultrasound guided FNA of the lesion
- excision biopsy of lymph node
clinical predictors of malignancy
- new thyroid nodule <20 or >50
- male
- nodule size increasing
- lesion >4cm in diameter
- history of head and neck irradiation
- vocal cord palsy
management for thyroid cancer
- thyroid lobectomy with isthmusectomy
- sub-total thyroidectomy
- total thyroidectomy
- TRA
risk stratification post-op
AMES
Age
Metastases
Extent of primary tumour
Size of primary tumour
what older patients are low risk
ones with:
- intrathyroidal papillary lesion
- minimally invasive follicular lesion
- primary tumour < 5cm
- no distant metastases
what patients are AMES high risk
- distant metastases
- extrathyroidal disease in papillary
- significant capsular invasion with follicular
- primary tumour >5cm in older patients
who gets thyroid lobectomy with isthmusectomy
- Papillary microcarcinoma ( < 1cm diameter)
- Minimally invasive follicular carcinoma with capsular invasion only
- Patients in AMES low risk group
who gets sub-total or total thyroidectomy
- DTC with extra-thyroidal spread
- Bilateral / multifocal DTC
- DTC with distant metastases
- DTC with nodal involvement
- Patients in AMES high risk group
post operative care
- 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
who gets whole body iodine scanning
patients who have undergone sub-total or total thyroidectomy
when is T4 and T3 stopped before whole body iodine scan
- T4 stopped 4 weeks prior
- T3 stopped 2 weeks prior
what happens in thyroid remnant ablation
- admitted to lead lined room
- pre-treated with rhTSH
- 2 or 3 GBq capsule of I-131 administered
- patient uses disposable cutlery etc
when are patients discharged from remnant ablation
when count rate <500cps at 1m
post TRA treatment
- patients maintained on T4
- aim to suppress TSH to <0.1 U/l and FT4 below 25
what does TRA do
- 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
