thyroid Flashcards
what is Primary hyperthyroidism
is when the problem is within the thyroid.
what is secondary hyperthyroidism
when the problem is with something else in the body which is affecting the thyroid like the pituitary or hypothalamus
the most common cause of hyperthyroidism
Graves disease is the most common cause of hyperthyroidism. It is an auto immune disease in which the body creates antibodies that bond to the TSH receptor thereby forcing the thyroid into excessive production.
medication that may cause thyrotoxicosis
amiodarone
hyperthyroidism gender and age
women > men 8:1; ages 20-40
second common cause of hyperthyroidism
toxic multinodular goiter
pregnancy, excessive dietary iodine intake, radiographic contrast, pituitary tumor, hashimoto’s thyroiditis
other causes of hyperthyroidism
thyroid cancer an graves
they can coincide
Grave’s disease 20-40% of pts will have…
-risk higher in who
chemosis(swelling of conjunctiva)
conjunctivitis
exophthalmos or proptosis
-risk higher in smokers
Eyes: stare lid lag with downward gaze upper eyelid retraction diplopia
hyperthyroidism
Heart Tachycardia AFib(8% of pts-usually elderly men w/ hrt d/s) Palpitations/forceful heartbeat Chest pain PVCs
hyperthyroidism
Skin Fine hair warm moist onycholysis (painless detachment of the nail from the nail bed) 3% have myxedema(dermal edema)
hyperthyroidism
myxedema in hypothyroidism too
change in bowel habits, menorrhagia, brittle hair, heat intolerance
hyperthyroidism
reflexes in hyperthyroidism
brisk HYPER-reflexia
osteoporosis clubbing finger swelling hypercalcemia/nephrocalcinosis gynecomastia AFib decreased libido/sperm count/impotence
Chronic symptoms hyperthyroidism/thyrotoxicosis
fever tachycardia vomiting/diarrhea dehydration muscle weakness confusion
thyroid storm
what can develop following oral or IV carbohydrates, IV dextrose, or excessive exercise
15% develop hypokalemic periodic paralysis lasting 7-72 hours typically in Asian and Native American Men
Hyperthyroid blood work
TSH extremely low (almost all the time) T4 (thyroxine) elevated T3 (triiodothyronine ) ESR elevated TSH receptor antibody elevated in Graves disease hypercalcemia
graves disease antibodies
peroxidase antibodies and thyroglobulin antibodies
radioactive iodine uptake study
increased uptake in graves and toxic multinodular goiter; uptake is more diffuse and symmetric in graves
avoid radioactive iodine uptake study in who
never should be done in pregnant women or in those with laboratory confirmed disease
imaging for hyperthyroidism
MRI and CT scanning of orbis is performed for severe or unilateral ocular signs or when causation may be other than graves
hyperthyroidism first line tx
Beta blockers are the first line of treatment and propranolol is the one you will hear about with hyperthyroidism and thyroid storm
what meds to control hyperthyroidism
Methimazole(MMI) and propylthiourcial (PTU) will actually control hyperthyroidism. radioactive iodine ablates thyroid(MC)
what meds to treat afib with hyperthyroidism
Digoxin to treat AFib
Warfarin to treat clotting with AFib
procedures for hyperthyroidism
Radioactive Iodine ablation
Surgical removal
drug of choice pregnancy or breast feeding with hyperthyroidism
PTU
radioactive iodine ablation for who
older pts, those with prior PTU/MMI reaction or failure, or poor compliance
older pts, those with prior PTU/MMI reaction or failure, or poor compliance: hyperthyroidism tx
radioactive iodine ablation
afib from hyperthyroidism tx
digoxin in large doses and beta blockers
opthalmopathy from hyperthyroidism tx
IV methylpredisone
RAI administration, pregnancy, trauma, sepsis, illness
all can precipitate a thyroid storm
thyroid storm mortality
high
PTU for thyroid storm- administer how
- orally but monitor for liver dysfunction
- IV Na iodine may be considered as well as IV hydrocortisone 50-100 mg every 6 hrs
- iodine may be administered as lugol solution
how to alleviate thyroid storm symptoms
propanolol
how to treat hypokalemic periodic paralysis
- medication and MOA
- avoid what
propanolol- normalizes serum potassim and phosphate levels and reverses paralysis within 3 hrs
- avoid IV dextrose or oral carbohydrates
heat vs cold intolerance
heat is hyperthyroidism
pts presents with afib, fever, delirium
- disease
- tx
thyroid storm
- anti-thyroid drugs, then iodine, IV esmolol, steroids, admit
hyperthyroidism intial test
TSH then T4
hyperthyroidism definitive tx
radioactive thyroid ablation or total thyroidectomy
- give levothyroxine (oral T4) and steroids
1st and 2nd most common endocrine disorder in US
1st is diabetes, 2nd is hypothyroidism
hypothyroidism is autoimmune and this causes what
-what causes the disease
antibodies against TSH receptors, antiperoxidase, and thyroglobulin
- anti-TSH antibodies cause the disease. antiperoxidase and antithyroglobulin are disease markers
most common cause of hypothyroidism
hashimotos thyroiditis
Medications that can cause hypothyroidism
Amiodarone which is structurally similar to thyroxine
Lithium
Propylthiouracil (PTU) and Methimazole – used to control hyperthyroidism
hypothyroidism labs
add CBC and BMP findings
what imaging
**TSH — elevated in primary hypothyroidism.
total T4 — decreased; free T4 — decreased
T3 — may be normal
Antithyroid peroxidase andAntithyroglobulin antibodies
CBC — may show anemia from iron def or chr disease (decreased absorption of iron and folate as well as GI motility)
BMP — low sodium(from alteration of renal tubular Na reabsorption)
imaging only if a concern for malignancy
up to 30% of downs pts will have this
hypothyroidism
labs in euthyroid state
nml or low free T4 and TSH
labs in primary hypothyroid state
low free T4 and elevated TSH
labs in secondary hypothyroid state
low free T4 and low/nml TSH
levothyroxine
converts to T3. adjust dose every 4-6 weeks based on TSH value
- assess for adrenal insufficiency and angina
severe hypothyroidism
- disorder
- presentation
- hallmark symptom
- mortality
myxedema crisis- obtundation, CO2 retention, maybe coma
** altered mental status
mortality 20-30%
pt presents with ... mental changes from confusion to coma convulsions hypotension hypothermia hypoventilation rhabdomyolysis and acute kidney damage hyponatremia hypoglycemia acute kidney injury
myxedema crisis
myxedema crisis tx
IV levothyroxine or thyroxine bolus
consider hydrocortisone if adrenal insufficiency is suspected
intubation if necassary
slow warming with warm blankets if necessary
suppurative thyroiditis organism
st aureus
thyroiditis dx tests
FNA with gm stain and culture
most common cause of sporadic goiter in kids
hashimoto
Sjogren’s syndrome
xerostomia — dry mouth
keratoconjuctivitis — dry eyes
hashimoto
- gender
- FH?
- what has the incidence risen over the past 50 years?
- female 6 times more likely
- may be familial
- related to increase in iodine content in diet
hashimoto may also present with what
- 30% will have sjogrens syndrome
- often concomitant with myasthensia gravis
most common painful thyroid gland
subacute
acute pain to thyroid glandular enlargement → dysphagia low grade fever fatigue dysphagia/otalgia for months ?thyrotoxicosis
Subacute Thyroiditis
50% will have thyrotoxicosis followed by hypothyroid followed by euthyroid within 12 months
50% will have thyrotoxicosis followed by hypothyroid followed by euthyroid within 12 months
Subacute Thyroiditis
EBV, influenza, coxsackie virus, mumps, measles, adenovirus
can all cause subacute thyroiditis
Subacute thyroiditis tx
- Aspirin is the first line drug of choice for pain and inflammation
- Propranolol (betablocker) for symptoms of hyperthyroid
- Levothyroxine for symptoms of hypothyroid
- no benefit of steroids
Subacute thyroiditis labs
markedly elevated ESR with antithyroid antibody titers low
thyroid: disease and etiology painful tender red fluctuant
Suppurative Thyroiditis
st aureus
hashimoto’s with a thyroid nodule
A patient with Hashimoto’s thyroiditis and a nodule in the thyroid should undergo FNA as the risk of associated thyroid cancer is significant
hypothyroid symptoms the thyroid becomes enlarged and hard dysphagia hoarseness pain dyspnea typically goes along with systemic fibrosis
Reidel thyroiditis
Reidel thyroiditis tx
short course of steroids for symptomatic relief
Tamoxifen for years after will result in partial to complete remission
woody assymetric hard thyroid
reidel
Reidel thyroiditis
- gender
- common or rare
80% females
the rarest
2 rare thyroiditis
suppurative and reidel
drug induced thyroiditis
- from what
- half life
- serum increase in what
- results in what
- amiodarone: causes thyroid dysregulation in 20% of pts due to iodine content
- 100 day half life
- cause serum increase of T4 by 20-40% during first month but causes cellular resistance to T4.
- resultant hypothyroid picture ensues with elevated TSH and symptoms typical of hypothyroidism
aspirin tx for what
subacute painful thyroiditis
tamoxifen tx for what
riedel thyroiditis
steroids tx for what
suppurative thyroiditis
leukocytosis and increased ESR for what thyroiditis
suppurative
subacute thyroiditis peaks what season
and ages
summer
young and middle aged women
believed to be autoimmune in nature
occurs in 7.2% of women post delivery
Postpartum thyroiditis
hyperthyroid followed by hypothyroid
painless
palpable goiter
beings 1-6 months postpartum
Postpartum Thyroiditis
beings 1-6 months postpartum
Postpartum Thyroiditis tx
self limiting
imaging in thyroiditis
- U/S used to distinguish thyroiditis from nodular goiter or possible malagnancy
- Radioiodine uptake scan may be helpful
thyroiditis labs
TSH
T4
Antithyroperoxidase levels increased in 90% of Hashimoto’s thyroiditis
Antithyroglobulin antibodies increased in 40% of Hashimoto’s thyroiditis
Thyroid autoantibodies
sed rate
Antithyroperoxidase levels increased in 90% of ___ thyroiditis
Antithyroglobulin antibodies increased in 40% of ___ thyroiditis
Antithyroperoxidase levels increased in 90% of Hashimoto’s thyroiditis
Antithyroglobulin antibodies increased in 40% of Hashimoto’s thyroiditis
endemic goiters
% of population
found where
10%
found in iodine deficient areas
sorghum, millet, maize, cassava, mineral deficiencies of selenium and iron
may enhance risk in iodine deficient states
solitary thyroid nodule
- gender
- size
- symptoms
- benign or malignant
females
over 1 cm
asymptomatic
benign usually. only 5% of palpable nodules are malignant
what solitary thyroid nodules are encapsulated
nodule of an adenoma is encapsulated, but the nodules of multinodular goiters are not encapsulated
most common type and rare type of solitary thyroid nodule
common: follicular adenoma
rare: papillary adenomas
hurtle cell
solitary thyroid nodule that has eosinophilic staining and has malignant potential
adenomas cancerous?
true adenomas are not cancer precursors
solitary thyroid nodule workup:
if TSH is low
assess for hyperthyroidism and undergo radionuclide thyroid scan
most sensitive test for a solitary thyroid nodule
high resolution ultrasonography
why u/s over a CT for a solitary thyroid nodule
u/s has higher accuracy, lower cost, and lack of radiation
solitary thyroid nodule has irregular or indistinct margins,
heterogenous echogenicity,
intranodular vascular margins, size over 1 cm
microcalcification, complex cyst patterns
suspect malignancy and should undergo ultrasound guided FNA
75% of solitary nodules show benign lesions
FNA of solitary thyroid nodule
75% of solitary nodules show benign lesions
solitary thyroid nodule found to be benign- tx?
T4 replacement is shown to decrease nodule size by 20%
what if the benign solitary thyroid nodule has no response to T4 therapy and the pt is euthyroid
discontinue
thyroid cancer
- gender
- prognosis
women 3:1
prognosis is worse in men
9% fatal
thyroid cancer could have hyper or hypothyroid symptoms
May have hyperthyroid symptoms due to excess T4 production including thyroid storm.
painless neck swelling and a palpable, single form nodule
thyroid cancer
thyroid cancer- diagnostic test
- RAIU to do what
- other test that is useful
- FNA diagnostic
- RAIU helpful to assess risk of malignancy and help plan surgical approach
- PET for detecting thyroid cancer mets with limited iodine uptake
- U/S to determine size and location as well as neck metastasis
thyroid cancer blood work
T4 normal except for Follicular cancer which produces T4
TSH normal except for Follicular cancer were the excess T4 will suppress TSH
There are tumor markers like serum carcinoembryonic antigen, calcitonin and serum thyroglobulin which can be followed.
thyroid cancer mets where? get what tests?
CT – for metastasis especially lung
MRI – for metastasis especially bone
U/S to determine size and location as well as neck metastasis
thyroid cancer tx
- Total or near total thyroidectomy
- Neck dissection and lymph node removal if indicated
thyroid cancer post op thyroidectomy tx
- Levothyroxine (synthetic T4) immediately post op for thyroidectomy patients
- Radioactive iodine ablation is used postoperatively for residual disease, metastatic disease and to prevent recurrence.
- Patients should receive whole body radioactive iodine scans. Remission is defined as two successive negative scans
medullary cancer thyroid cancer pts
Those with medullary cancer should have family members get a genetic work up and thyroid surveillance
Radioactive iodine ablation for brain mets
It should be noted that this is ineffective with mets to the brain which must be removed surgically with gamma knife
- childhood irradiation to head and neck
- FH, gardner syndrome, MEN type II syndrome
- confers a 25 fold increase in thyroid cancer and may emerge 10-40 post exposure
- other risk factors for thyroid cancer
thyroid cancer
- most common
- MEN
- most aggressive
- least aggressive
- most common is papillary
- MEN is Medullary
- most aggressive is anaplastic
- least aggressive is papillary
thyroid cancer
- early mets
- lymphatic spread
- slow growing
- rapidly enlarges
- early mets is medullary
- lymphatic spread- papillary
- slow growing- papillary
- rapidly enlarges- anaplastic
thyroid cancer
- good prognosis
- found in older pts
- may cause thyroid storm
- childhood head/neck radiation
- good prognosis is papillary and follicular
- found in older pts is anaplastic
- may cause thyroid storm is follicular
- childhood head/neck radiation is at risk for papillary
thyroid cancer
- found in calcitonin producing C cells
- often causing dysphagia or vocal cord paralysis
- often mets to lung, brain, bone, liver
- rapidly enlarges and early mets to local and distant sites
- found in calcitonin producing C cells is medullary
- often causing dysphagia or vocal cord paralysis is anaplastic
- often mets to lung, brain, bone, liver is follicular
- rapidly enlarges and early mets to local and distant sites is anaplastic
