Thyroid Pathology Flashcards
Describe the descent of thyroid gland
foramen caecum to normal location via thyroglossal duct
What happens if if fails to descend?
lingual thyroid
What happens if there is excessive descent?
Retrosternal location in mediastinum
What is a thyroglossal duct cyst?
Midline swelling above where thyroid should be
What are C cells and what do they produce?
Parafollicular cells
Larger than follicular cells
Produce Calcitonin
Describe the process of stimulation of thyroid hormones
Hypothalamus releases Thyrotropin Releasing Hormone
TRH acts on anterior pituitary which releases thyroid stimulating hormone
TSH
TSH acts on follicles and T3/4 is released
Where do thyroid hormones bind at target cells?
Enter nucleus and bind to Thyroid Response Elements on specific genes to increase BMR
Causes of Hyperthyroidisms (5)
Graves' Tumours Thyroiditis Factitious reasons Struma Ovarii
Presentations specific to Graves’ (2)
Pretibial myxoedema
Exophthalmos
Causes of hypothyroidism (5)
Hashimoto's Iodine deficiency lithium drugs Post surgery congenital
Antibody in hashimoto’s?
anti-TPO (against thyroid peroxidase enzyme that adds iodines to tyrosine residues)
What is hashitoxicosis?
Phase of Hashimoto’s where colloids are destroyed and burst releasing thyroid hormones which causes transient hyperthyrioidim
Name the types of Carcinomas found in thyroid (4)
Papillary
Follicular
Medullary
Anaplastic
Paraneoplastic syndromes from Medullary Carcinoma? (2)
Diarrhoea due to VIP production
Cushing’s due to ACTH
How is papillary carcinoma spread?
lymphatics
