Thyroid Disease Flashcards
What are the 2 most common types of thyroid cancer?
Papillary
Follicular
Thyroid cancer is more common in males. True/False?
False
Females
What aetiology has a strong association with thyroid cancer?
Radiation exposure
What is the main presenting complaint of thyroid cancer?
Palpable nodule in the neck
Follicular thyroid cancer is more common than papillary variant. True/False?
False
Papillary is most common
How does papillary thyroid cancer tend to spread?
Lymphatics
Also haematogenous
The incidence of follicular thyroid cancer are higher in people deficient of which chemical?
Iodine
Lymphatic spread of follicular thyroid cancer is rare. True/False?
True
What is the main investigation for thyroid cancer?
Ultrasound-guided fine needle aspiration
Can do lymph node biopsy if spread
If the thyroid cancer lesion is greater than _cm, there is clinical prediction of malignancy
4cm
What are the main surgical techniques for thyroid cancer?
Lobectomy (uncommon)
Sub-total thyroidectomy
Total thyroidectomy
A 36 yr old man with thyroid cancer with no metastases is AMES high risk. True/False?
False
Low risk
All patients with metastases of thyroid cancer are AMES high risk. True/False?
True
What type of thyroid tumours may be treated by lobectomy?
Papillary micro-carcinoma
Minimally invasive follicular carcinoma
AMES low risk
Calcium is checked post-op for thyroid cancer. At what level of calcium is replacement initiated?
Less than 2 mmol/L
Why is iodine body scanning done for post-op thyroid cancer?
To detect residual cancer cells
How long before an iodine scan must T3 and T4 be stopped?
Stop T4 4 weeks prior
Stop T3 2 weeks prior
TSH must be elevated for an iodine scan. True/False?
True
What non-surgical technique can be used for thyroid cancer destruction following surgery?
Thyroid remnant ablation
Thyroid swellings move on swallowing. True/False?
True
Thyroglossal swellings move with the tongue. True/False?
True
Autoimmune thyroid disease is the commonest cause of hypo/hyper -thyroidism. True/False?
True
In hyperthyroidism, TSH levels are high. True/False?
False
TSH is low in hyperthyroidism, and high in hypothyroidism
Why is TSH low in hyperthyroidism?
Hyperthyroidism causes excess T4, so pituitary produces less TSH in order to try and compensate
In the context of pituitary gland failure, would TSH levels be high or low in hypothyroidism?
Low
pituitary can’t compensate
What is myxoedema?
Severe hypothyroidism
N.B. pretibial myxoedema is seen in Grave’s disease due to thyrotoxicosis
Incidence of hypothyroidism is higher in people with high/low iodine
Low iodine is assoc. with hypothyroidism
What is the main goitrous cause of hypothyroidism?
Hashimoto’s thyroiditis (chronic/autoimmune thyroiditis)
List some drug-induced causes of hypothyroidism
Amiodarone
Aminosalicyclic acid
Lithium
Iodides
What are the 2 main origins of secondary hypo/hyper -thyroidism?
Hypothalamus disease
Pituitary disease
What happens in Hashimoto’s thyroiditis?
Autoimmune destruction of thyroid gland, causing reduced thyroid hormone production
Which antibody is very specific for Hashimoto’s thyroiditis?
Thyroid peroxidase antibodies (anti-TPO)
List some clinical features of hypothyroidism
Sparse hair Dry skin, puffiness Cold intolerance Tiredness Vitiligo Constipation Reduced heart rate Weight gain
Outline treatment of hypothyroidism
Restore metabolic rate
Thyroxine (T4) 50-100 micrograms
TSH is useful to mark therapeutic success in secondary hypo/hyper -thyroidism. True/False?
False
It will be low because problem is with pituitary
Who does myxoedema coma predominately affect?
Elderly women with longstanding untreated hypothyroidism
What is the main autoimmune cause of hyperthyroidism?
Grave’s disease
List clinical features of hyperthyroidism
Agitation/irritability/anxiety Palpitations Heat intolerance/sweating Tremor Loose bowels Exopthalmus, lid lag, proptosis Weight loss
What causes Grave’s disease?
Unknown mix of genetics + environment
Autoimmune destruction
Which antibodies are fairly specific for Grave’s disease?
Anti-TPO antibody
Anti-TSH-receptor antibody
What is the characteristic view of Grave’s disease on scintigraphy?
Symmetrical, smooth goitre
Looks like a butterfly
What drugs are given for hyperthyroidism?
Carbimazole
Propylthiouracil in pregnancy
B-blocker if arrhythmic
Medullary thyroid carcinomas are derived from which cells?
C cells