Thyroid Correlates Flashcards
HypoT CM
generalized
matrix glycosaminoglycans accumlate in
look for labs w
slowing of metabolic processes
interstitial space of many tissues
high TSH, low T4, elevated thyroid AB
Iatrogenic causes of HypoT
Iodine
Drugs
Infiltrative dz
thyroidectomy, radioiodine therapy, external radiation
deficiency/excess
Li/Amiodarone
Hemochromatosis, sarcoid
Tx hypoT w
why not T3
levothyroxine (synth T4)
body converts T4 to T3 in peripheral tissues
Levothyroxine
converted to active metabolite
T4/T3 will bind to
exert effects through
L-triiodothyronine (T3)
nuclear, thyroid receptor
control of DNA trxn and protein synthesis
lab test indicating Euthyroid sick syndrome
treating myxedema coma considered
has ____ MR
low serum T4, free T4 and T3 and TSH
IV hydrocortisone, IV T4 high dose
high
Graves dz on iodine uptake scan
High uptake indicates
Low uptake indictes
possible cause of high uptake
possible cause of low uptake
diffuse uptake w enlargement
new hormone synth by thyroid
release of preformed hormone, exogenous ingestion, extrathyroidal synthesis
Graves, toxic adenoma/goiter, pituitary ademoma
Thyroiditis, exogenous thyroid hormone intake, ectopic hyperT
labs of Graves
thyroid gland growth w thyroid hormone synthesis/release results in
antithyroid drugs include
can cause
tx HyperT
suppresed TSH, high T4, anti-TSI positive
inc radioactive iodine uptake
methimazole, propylthiouracyl
agranulocytosis
I131 ablation (destroys gland), total thyroidectomy
PTU ihibits ______ by blocking _______
Does not inactivate ______ in blood/thyroid or w replacement hormones
Methimazole inhibits ______ by blocking _______ in thyroid gland
blocks synthesis of ______ but does not ______
synthesis of TH, conversion of T4 to T3 in peripheral tissues
T4/T3
synthesis of TH, oxidation of iodine
T4 and T3, inactivate circulating T4/T3
Additional problem to consider in pregnant woman w PTU
Methimazole
PPP
Teratogenic effects, 1st trimester
2nd trimester
PTU Primary Pregnancy
Thyroid storm sx
TX
Thionamide
methimazole is
PPP
Fever, CNS, GI effects, HTN
BB (propanolol), supportive, glucocorticoid
in life threatening case
PTU>methimazole
otherwise preferred- lower hepatic toxicity, restores euthyroid more quickly
Propanolol, PTU (peripheral conversion), Prednisone
Potential cause of deQuervians thyroiditis
Phases
HyperT presents w, lab values
Damage to _____, breakdown of
lasts until _____, about
Thyroid radioiodine uptake is
viral/post viral inflammation
tender, dissue goiter (high T4 w/wo T3)
thyroid follicular cells, stored TG
T4/T3 depleted, 2-6wks
low
HypoT phase DT
Followed by
low radioactive iodine uptake w high serum TG leads to damage in the
tx DT
monitor thyroid fxn test every
synth of TH is inhibited due to lack of TSH
recovery phase (if not permanent)
thyroid follicle cells w breakdown of TG- releases T4/T3
NSAID or prednisone (severe pain)
2-8 wks to confirm resolution of hyperT, hypoT, euthyroid
Ddx for solitary thyroid nodule
Benign nodule
Follicular lesion/atypia
Follicular neoplasm
Malignancy
Factors that inc likelihood of malignancy
Hx of
Childhood
Total body
FH of
Mass is
Sx include
rapid growth of neck mass
H/N radiation
radiation for BMT
thyroid ca, syndromes
fixed, hard
obstructive, cervical LAD, hoarse
Factors that inc likelihood of nodule being benign
Gender
Age
No malignant features
woman (ca more likely in men)
high in adults >60 or less than 30
