Thyroid Flashcards
The Superior thyroid artery is the first branch of the __________?
external carotid artery
Origin of inferior thyroid artery
thyrocervical trunk
what is the ima artery origin and destination
origin: innominate
destination: isthmus
what does the superior laryngeal nerve innervate?
what happens with injury to this nerve?
- cricothyroid muscle
2. loss of projection and voice fatigue
path of right recurrent laryngeal nerve?
follows vagus and loops around right subclavian artery
path of left recurrent laryngeal nerve
loops around aorta
is T3 or T4 more plentiful in the periphery?
T4
is T3 or T4 more active?
T3
does the thyroid make more T3 or T4?
80% T4, 20% T3
embryologic origin of the thyroid
4th endodermal POUCH
what is the treatment for thyroid storm?
beta blockade and lugol’s solution, cooling blankets.
pre-op lugols can prevent thyroid storm
what is the workup of thyroid nodule?
ultrasound and FNA
concerning features of thyroid nodule on US?
hypoechoic, micro-calcification, irregular margins, unorganized vasculature, lymphatic invasion
what are the stages of Bethesda criteria and treatment?
- indeterminate - repeat FNA
- Benign - repeat US in 6-12 mos
- AUS/FLUS - repeat FNA
- follicular neoplasm - lobectomy
- suspicious for malignancy - lobectomy
- malignancy - total thyroidectomy
Tx of hyperthyroidism
PTU or MMI
PTU side effects?
aplastic anemia, agranulocytosis
MMI side effects?
cretinism, aplastic anemia, agranulocytosis
is PTU or MMI safe during pregnancy?
PTU - does not cross placenta
pathophysiology of graves disease?
antibodies against TSH receptors
treatment of multi-nodular goiter?
total or subtotal thyroidectomy
pathophys of Hasimoto’s thyroiditis?
Tx?
antithyroid antibodies
Tx with hormone replacement
cause of subacute granulomatous thyroiditis?
treatment?
viral cause
treat with NSAIDs
Most common thyroid malignancy
papillary thyroid carcinoma
histology of PTC?
orphan annie nucleus, psammoma bodies, nuclear inclusions
treatment of PTC?
total thyroidectomy +/- level VI dissection
–can follow thyroglobulin for surveillance, postop radioiodine tx, removal of multifocal disease
tx for follicular thyroid cancer?
lobectomy +/- MRND for + nodes, post op RAI - FNA unreliable in many cases
follicular thyroid cancer - hematogenous or lymphatic spread?
hematogenous
PTC - hematogenous or lymphatic spread?
lymphatic
what cells cause medullary thyroid cancer ?
parafollicular C cells
gene associated with medullary thyroid cancer
RET proto-oncogene
Tx of medullary thyroid cancer?
total thyroidectomy with central neck dissection - MRND if + LNs
surveillance for medullary thyroid cancer?
CEA and calcitonin. calcitonin takes ~ 8wks to come down
when should patients with MEN2A and MEN2B get total thyroidectomy?
by 5 years of age typically
