Thyroid lumps and diagnosis Flashcards
Describe the anatomy of thyroid gland • Understand thyroid physiology • Discuss common causes of thyroid swellings • Understand the general approach, laboratory and Imaging studies in the evaluation of thyroid swellings • Describe clinical and imaging features of thyroid swellings • Outline treatment strategies
When does the first endocrine gland (thyroid) develop?
24 days
What structure thickens to begin the development of the thyroid?
Endodermal thickening in the primordial pharynx
What divides into two lobes?
Thyroid diverticulum
How is the thyroid attached to the tongue?
By the thyroglossal duct
What occurs at week 7?
Thyroglossal duct degenerates and is replaced by the pyramidal lobe in 50% of people
Where does the thyroid gland lie anatomically?
Anterior to the 2nd/3rd tracheal ring
What occurs are week 7?
Colloid in thyroid follicles
Which cells make up the thyroid?
Follicular cells
Para-follicular cells
What do follicular cells do?
produce and secrete Triiodothyronine (T3) and etraiodothyronine or Thyroxine (T4)
What do T3 and T4 do?
Regulates metabolism of various tissues and organs
What do para-follicular cells do?
Release calcitonin
What is the function of calcitonin?
important hormone for maintaining Ca homeostasis
What role does the hypothalamus play in the regulation of thyroid hormone synthesis?
Releases thyroid releasing hormone which stimulates pituitary gland
What role does the pituitary gland play in the regulation of the thyroid hormone synthesis?
releases thyroid stimulating hormone
Name the metabolic effects of the thyroid hormones?
Lipid and carbohydrate metabolism • Growth • Development (foetal and neonatal brain) • Cardiovascular system • Central nervous system • Gastrointestinal system • Reproductive system • Bone turnover
Name the etiological classification of thyroid swellings
Simply goitre
Inflammatory
Neoplastic
Other
What are the potential anomalies of thyroid gland development?
Persistence of thyroglossal duct results in thyroglossal cyst or fistula
• Rarely thyroid bud fails to descend to form the lingual thyroid
• May descend too far into the mediastinum to form the retrosternal goitre
• Thyroid bud may fail to divide into two resulting in absent thyroid lobe
Name the benign causes of thyroid swellings
- Multinodular goitre
- Hashimoto’s thyroiditis
- Cysts; colloid, simple, haemorrhagic - Follicular adenoma
- Oxyphil adenoma