What are the different histological types of thyroid cancer ?
- Papillary - 76%
- Follciular - 17%
- Medullary - 3%
- Anaplastic - 2%
What is a differentiated thyroid cancer ?
- This is when the cells in these cancers looks a lot like normal thyroid tissue, they are well differentiated and have a good prognosis.
- These cancers develop from thyroid follicular cells
What are the 2 main types of DTC?
Papillary and follicular
What DTC's take up and secrete ?
Take up iodine and secrete thyroglobulin
What has a strong association with predisposing people to developing thyroid cancers ?
Exposure to radiation
What do patients with thyroid cancer tend to present with on examination?
Majority with palpable nodules
What is the most common class of thyroid cancer ?
Describe the typical route of spread for papillary cancers
Tend to spread via lymphatics - 40% of patients will have lymph node metastases at presentation
What condition is papillary thyroid cancers associated with ?
How do follicular thyroid cancers tend to spread ?
In what areas is there a higher incidence of follicular thyroid cancers ?
Areas of relative iodine deficiency
The prognosis of papillary and follicular thyroid cancers is relatively similar what is it ?
Very good - 10 year mortality < 5%
What investigation is done to diagnose a DTC ?
US guided FNA of the lesion
What are some of the clinical signs of malignancy in thyroid cancer ?
- New nodule < 20 or > 50
- Nodule increasing in size
- Lesion > 4 cm
- History of head and neck irritation
- Vocal cord palsy
What is the treatment of thyroid cancers ?
- Sub-total or total thyroidectomy
- Lobectomy with isthmectomy
What is used to classify patients as high or low risk patients post-op?
- Extent of primary tumour
- Size of primary tumour
Give some examples of low risk AMES patinets
- Young patients no evidence of metastases
- Older patients no metastases, or minimally invasive lesion
- Tumour < 5cm
Give some examples of high risk AMES patients
- All patients with distant metastases
- Extrathyroidal disease in patients with papillary cancer
- Tumour > 5cm in older patients
When would you do a thyroid lobectomy with isthectomy ?