Thyroid Flashcards
TFT reference ranges
TSH 0.33-4.5 umol/L
free T4 10.2-22 pmol/L
free T3 3.2-6.5 pmol/L
High TSH, Low T4
Primary hypothyroidism
Atrophic, subacute, Hashimoto’s, postpartum, Riedel thyroiditis
High TSH, N T4
Treated or subclinical hypothyroidism
High TSH, High T4
TSH secreting tumour or thyroid resistance
Low TSH, High T4/T3
Primary Hyperthyroidism
Graves, Toxic multinodular goitre, toxic adenoma, drugs, ectopic
Low TSH, N T4/T3
Subclinical hyperthyroidism
May progress to primary hypo, especially if anti-TPO positive
High then Low TSH, Low T4/T3
Sick euthyroidism
Body tries to shut down metabolism as thyroid gland has reduced output
N TSH, abnormal T4/T3
Assay interference, changes in TBG, amiodarone
Medical management of hyperthryoidism
Symptom management
Carbimazole
Efficacy and risks of radioiodine for hyperthyroidism
Main pre-op requirement and post-op treatment of surgical hemi/total thyroidectomy
What is a thyroid storm?
Hypothyroid management
Thyroid replacement
Summarise causes of hyperthyroidism
Summarise causes of hypothyroidism
Risk factors for thyroid neoplasia
Solitary, solid, young, male, cold nodules
Most common thyroid cancer
Papillary thyroid cancer
Papillary thyroid cancer age of onset
20-40
Papillary thyroid cancer tumour marker
Thyroglobulin
Papillary thyroid cancer spread
LNs and lung
Papillary thyroid cancer histology
Psammoma bodies
Orphan annie eyes
Papillary thyroid cancer Mx
Surgery +/- radioiodine, thyroxine
Follicular thyroid cancer age of onset
40-60 years
Follicular thyroid cancer key feature
Well differentiated with early spread via blood
Follicular thyroid cancer tumour marker
Thyroglobulin
Follicular thyroid cancer histology
Small follicles
Normall thyroid appearance
Follicular thyroid cancer Mx
Surgery + radioiodine + thyroxine
Medullary thyroid cancer age of onset
50-60 years
Medullary thyroid cancer key association
20% MEN2
Medullary thyroid cancer definition
Neuroendocrine neoplasm derived from parafollicular C cells secreting calcitonin
Medullary thyroid cancer tumour marker
CEA, calcitonin
Medullary thyroid cancer histology
Sheets of dark cells
Amyloid deposition (product of calcitonin catabolism)
Medullary thyroid cancer Mx
Screen for phaeo (MEN2) pre-op
Surgery
Node clearance
Medullary thyroid cancer Mx
Screen for phaeo (MEN2) pre-op
Surgery
Node clearance
Anaplastic thyroid cancer age of onset and prognosis
Elderly, most die within a year
Anaplastic thyroid cancer spread
very aggressive
local, LNs, blood
Anaplastic thyroid cancer histology
undifferentiated follicles
Large pleomorphic giant cells
Spindle cells with sarcomatous appearance
Thyroid lymphoma (MALToma) key association
Chronic Hashimoto’s
How to distinguish the 3 different types of MEN
