Thyroid neoplasms Flashcards
types of neoplasms
Adenomas
- follicular adenoma
Carcinomas
- papillary,
- follicular,
- medullary
- anaplastic
what is an adenoma?
a discrete solitary mass - an incidental finding, if large it can cause local symptoms like dysphagia
encapsulated by a surrounding collagen cuff
composed of neoplastic thyroid follicles
usually non-functional mass
can secrete thyroid hormones - thyrotoxicosis - TSH independent
what can it be hard to distinguish a adenoma from?
a dominant nodule in a multinodular goitre and follicular carcinoma
what causes an adenoma?
a few <20% have mutant ras or PIK3CA, potential relationship to carcinoma
mutations of TSHR signalling pathway in functional adenomas
- activating (fain of function) TSHR and G proteins
- increase cAMP levels
what causes a thyroid carcinoma?
environmental associations
- ionising radiation (papillary carcinoma)
- iodine deficiency (follicular carcinoma)
genetic features
