Thyroid pathology Flashcards
What embryological abnormalities can occur in thyroid development?
Some cysts, usually non-problematic, upon inflammation might cause problems like compression of airway
C cells (Parafollicular cells)
Clearer cytoplasm, larger cells
Secrete calcitonin –> promotes absorption of calcium by skeleton and prevents bone resorption by osteoclasts
What is MOA of TSH, T3 and T4?
Thyroiditis is mostly an autoimmune condition
as in the case of Hashimoto’s thyroiditis (hypo) and Grave’s disease (hyper)
What is the pathophysiology of Hashimoto’s thyroiditis?
it might be preceded by transient hyperfunction (as the follicular cells start to be damaged, they may initially produced a lot of hormones)
- They are at risk of increasing chance of lymphomas within thyroid
How can thyroiditis and neoplasia be differentiated pathologically?
Look at capsules in thyroid
In thyroiditis capsules are intact as inflammation is contained, whereas in neoplasia they are usually affected
What is the more common way of taking thyroid tissues?
FNA thyroid
local anaesthesia + aspiration (although sometimes purely blood is aspirated)
What are the antibodies for Hashimoto’s and Grave’s respectively?
Anti-TSH receptor antibodies (specific to Grave’s)
Anti-TPO and anti-thyroglobulin are more for Hashimoto’s thyroiditis
Goitre
A way to compensate for low T3/T4, usually due to iodine deficiency
Enlargement is proportional to duration and degree of iodine deficiency
More commonly endemic in mountain ranges like Himalayas and Andes
Multi-nodular goitre
Usually as a result of untreated long-term diffuse goitre
Some nodules may become autonomous (secreting hormones even without stimulants), leading to hyperthyroidism
What is a delineating factor between carcinoma and adenoma?
Adenomas are usually contained in a collagen cuff, carcinomas do tend to break capsules (except for follicular carcinoma - but might invade into blood vessels)
Follicular carcinoma tend to spread via bloodstream to other sites
What are the four main types of thyroid malignancy?
Papillary (75-85%) - metastasise via lymphatics [hence not surprisingly most common site of metastasis is lung] (looks like Neji eye under microscope)
Follicular (10-20%) - metastasise via bloodstream
Anaplastic (<5%) : de novo or dedifferentiation, very invasive, poor prognosis
Medullary (5%) - from parafollicular C cells (a neuroendocrine tumour, produce amyloid deposits)
Thyroid condition history taking
Neck symptoms
*Lump size, pain, soft/hard, mobile
*Duration/growth rate
*Voice/Stridor
*Swallow
*Other lumps
Systemic symptoms - think excess thyroxine or PTH
PMHx - metastatic spread to thyroid or neck
Medication -
Family history
Other
Thyroid examination
What are blood tests for thyroid cancer?
thyroid stimulating hormone
What is a surgical perspective towards classification of thyroid neoplasia?
