Hyperthyroidism Flashcards
Which antibodies might be present in thyroid disease?
Anti-thyroid peroxidase (anti-TPO) antibodies
Anti-thyroglobulin antibodies
TSH receptor antibodies
When might anti-TPO antibodies be present?
Grave’s disease
Hashimoto’s thyroiditis
When might anti-thyroglobulin antibodies be present?
Grave’s disease
Hashimoto’s thyroiditis
Thyroid cancer
–> may be present in normal individuals so measuring them is of limited use
When might TSH receptor antibodies be present?
They are the cause of Grave’s Disease
Which modalities of imaging are used in thyroid disease?
US of thyroid
Radioisotope scan
When is US useful for thyroid disease?
Diagnosing thyroid nodules
- distinguishing between cysts (fluid filled) + solid nodules
Guiding biopsy of a thyroid lesion
When is a radioisotope scan used in thyroid disease?
Investigating hyperthyroidism + thyroid cancers
How does a radioisotope scan work?
Patient given radioactive iodine orally or IV
The most active the thyroid cells, the faster the iodine is taken up
Gamma camera used to detect gamma rays emitted from the radioactive iodine
–> functional thyroid information
What might be seen on radioisotope scan indicating what pathology?
Diffuse uptake –> Grave’s
Focal high uptake –> toxic multi nodular goitre + adenomas
Cold areas (low uptake) –> thyroid cancer
What are the causes of primary hyperthyroidism?
Grave's disease Toxic multinodular goitre Solitary toxic thyroid nodule Thyroiditis: - De Quervain's - Hashimoto's - postpartum - drug-induced
What is Grave’s disease?
Autoimmune condition
TSH receptor antibodies mimic TSH
Most common cause of hyperthyroidism
What is toxic multi nodular goitre?
aka Plummer’s disease
Nodules on thyroid gland that act independently of the normal feedback system –> continuous production of excessive thyroid hormone
What are the universal features of hyperthyroidism?
Anxiety + irritability Sweating + heat intolerance Tachycardia Weight loss Fatigue Frequent loose stools Sexual dysfunction
What are the unique features of Grave’s disease?
(due to TSH receptor antibodies)
- diffuse goitre (without nodules)
- Graves eye disease
- bilateral exophthalmos
- pretibial myxoedema
What is pretibial myxoedema?
Deposits of mucin under the skin on anterior leg –> discoloured, waxy, oedematous appearance