Parathyroid hormone and other thyroid issues Flashcards
(22 cards)
Most common type of thyroid carcinoma?
Papillary (makes up 80%)
Then follicular (10-20%)
Then medullary (5%)
Then anaplastic<5%
Who gets papillary thyroid carcinomas?
Usually women between the age of 35-45.
Risk factor for papillary thyroid carcinoma?
Ionising radiation as a child
Histology of papillary thyroid carcinoma?
Comprised of papillae lined by cells with clear, orphan Annie eye nuclei and nuclear grooves.
Associated with psammona bodies.
Prognosis of papillary thyroid carcinoma?
Often spreads by cervical lymph nodes but prognosis is excellent
10 year survival >90%
Follicular carcinoma histology?
Malignant proliferation of follicles surrounded by a fibrous capsule with invasion through the capsule.
How would you distinguish between follicular adenoma and follicular carcinoma?
The invasion through the capsule wall is characteristic of carcinoma.
Investigations into follicular carcinoma?
Carcinoma must be examined microscopically. FNA only takes cells and therefore you cannot distinguish between adenoma and carcinoma.
How does follicular carcinoma metastasise?
via blood.
Describe a follicular adenoma?
Benign proliferation of follicles surrounded by a fibrous capsule. Usually non-functional.
Describe a medullary carcinoma?
Malignant proliferation of parafollicular C cells. Associated with MEN.
Calcitonin often deposits in the tumour as amyloid.
What do C cells secrete?
Calcitonin.
What does calcitonin do?
Lowers serum calcium.
Describe an anaplastic carcinoma?
Undifferentiated malignant tumour of the thyroid. Usually in the elderly.
How do anapaestic carcinomas usually present?
Often by invading local structures causing dysphagia.
Prognosis of anaplastic carcinoma?
POOR
What is myxoedema coma?
Typically affects old ladies with long standing unrecognised or untreated hypothyroidism.
ECG- bradycardia
-low voltage complexes
varying degrees of heart block
Type 2 respiratory failure
Treatment of myxoedema coma?
ABCDE
Passively rewarm- aim for slow rise in body temp
Monitoring- fluids- broad spectrum AB
What is thyroid storm?
Medical emergency almost always caused by graves disease.
Severe hyperthyroidism- respiratory and cardiac collapse
-hyperthermia
-exaggerated reflexes
-may require ventilation
-could be associated with underlying infection
Treatment of thyroid storm?
Fluid resus if dehydrated
Give propanolol (beta blockers)
Lugois iodine
Glucocorticoids
What can amiodarone induce?
Thyrotoxicosis-occurs more frequently in areas with low iodine intake.
hypothyroidism- high iodine intake
What cells are the parathyroid glands composed of?
Chief cells- secrete PTH.
