Differentiated Thyroid Cancer Flashcards
What is Differentiated Thyroid Cancer (DTC)?
Umbrella term that refers to papillary (most common) and follicular (2nd most common) variants of thyroid cancer
Differentiates means good prognosis, generally
Characteristics of DTCs?
Most take up iodine and secrete thyroglobulin
DTCs are TSH driven
Occurrence of DTCs?
Slightly more common in females:
• In females, rates increase from 15-40 years and then plateau
• In males, there is a steady increase with age
There is a lower incidence in Afro-Americans and they are uncommon in childhood; weak assoc. with thyroid adenomata, conditions assoc. with chronic TSH elevation and increasing parity
Strong assoc. with radiation exposure
Lifestyle in relation to DTC?
No assoc. with diet, other proven malignancies, FH, smoking or other lifestyle factors
Presentation of DTC?
Most present with palpable nodule(s)
Rarely, they can be an incidental finding on histological section of thyroidectomy tissue, i.e: this had been done due to another thyroid problem
Spread of papillary thyroid carcinoma?
Tends to spread via LYMPHATICS
There can be haematogenous spread to the lungs, bone, liver and brain
Assoc. diseases with papillary thyroid cancer?
Assoc. with Hashimoto’s thyroiditis
Spread of follicular thyroid carcinoma?
Tends to spread HAEMATOGENOUSLY
Lymphatic spread and lymph node enlargement are relatively rare
Assoc. problems with follicular carcinoma?
Incidence is slightly higher with iodine deficiency
Ix of thyroid carcinoma?
Usually, USS-guided FNA of the lesion
May involve excision biopsy of lymph nodes
If vocal chord palsy is clinically suspected, pre-operate laryngoscopy
Clinical predictors of malignancy?
- New thyroid nodule <20 or >50 years of age
- Male
- Nodule increasing in size
- Lesion > 4cm diameter
- History of head and neck irradiation
- Vocal cord palsy
Treatment of choice for DTC?
Gold standard treatment:
Surgery +/- radioiodine (TRA) + life long follow-up
Surgical options?
Thyroid lobectomy with isthmusectomy (some cancer cells may remain)
Sub-total thyroidectomy (likely the best option)
Total thyroidectomy (risk of damage to other structures)
Risk stratification of DTC patients?
AMES is used to stratify patient as low or high risk: Age Metastases Extent of primary tumour Size of primary tumour
Patient that fall into AMES low risk category?
Survival is very good in this group:
• Younger patients (men <40, women <50) with no evidence of metastases
• Older patients with intra-thyroidal papillary lesion OR minimally invasive follicular lesion and primary tumour <5cm and no distant metastases