Term
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Definition
And then here's a cross-section of the thyroid gland, what it actually looks like pathology-wise. So you have the thyroid follicle. You have the follicular cells over here. And then you have the C cells on top that secrete calcitonin.
And then inside the thyroid follicle is colloid. So that's important to know. Certain biopsies will bring back colloid, which is perfectly normal. So brief overview on that. |
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Term
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Definition
• You can’t feel a normal sized thyroid
• You can feel an enlarged thyroid from Graves’ disease and thyroid nodules, usually if they are >1cm
• A thyroid with multiple thyroid nodules will feel “lumpy, bumpy, and asymmetric”
• Thyroid ultrasound is very helpful and should be the first test ordered when evaluating the anatomy of the thyroid gland!!! |
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Term
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Definition
| So, histology of the thyroid, kind of the same picture again, with the colloid, the follicular cells, the C cells. And then how the thyroid produces hormones is the next slide. So C cells of the thyroid produce calcitonin, which helps deposit calcium from the serum into the bone. And then this is the steps that go into the biosynthesis of the thyroid hormones. And I listed them here, and then the next slide will show you the picture representation of it. |
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Term
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Definition
• C-cellsofthethyroidproducecalcitonin,whichhelps deposit calcium from the serum into the bone
• Sixstepsinbiosynthesisofthyroidhormones:
1. Trapping of iodide from ingestion or deiodination of thyroid hormone (recycling)
2. Oxidation of iodide to iodine along with Tg synthesis
3. Organification of iodine into monoiodotyrosine and diiodotyrosine with tyrosine
4. Coupling of iodinated precursors forming tri and tetra
5. Storage in colloid with Tg
6. Hormone release with TBG (thyroxine binding protein) |
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Term
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Definition
| So, this is a picture representation of that. So this says step one is release, but step one's really over here, the trapping of iodine into the cell. And then you have moving over here to the organification process, moving to mono and di. And then here you go, you have your T3, T4, tetra and the fourth one. And then you have the endocytosis. It goes back into the cell where it's stored and then gets released. So just a overview of that. |
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Term
| Action of Thyroid Hormones |
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Definition
• Stimulate cell respiration
• Thermogenic
• Potentiate action of epinephrine
• Stimulate somatic growth
• Involved in normal development of CNS (cretinism) |
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Term
| Overview of the Thyroid Hormonal Axis |
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Definition
- Stimulatory factors
• IncreasedTRH
• Decreased T4/T3
- Primary inhibitory factors
• Decreased TRH
• Increased T4/T3
• Cortisol
• Inflammatory cytokines
• Dopamine
• Octreotide |
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Term
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Definition
• TSH—released from the pituitary to stimulate the thyroid gland to produce:
• T4—available in free and total levels (with and without TBG); predominant thyroid hormone secreted from thyroid. Half-life is 1 week
• T3—also available in free and total levels; most potent and comes from the thyroid and T4 to T3 conversion. Half-life is 18 hrs.
• T4 can be converted into inactive metabolite, reverse T3—rT3 |
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Term
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Definition
released from the pituitary to stimulate the thyroid gland to produce:
• Total T4 and T3 are affected by TBG levels:
- Increased TBG levels from pregnancy, estrogen, OCPs leading to falsely elevated TT4/TT3
- Decreased TBG levels: cirrhosis, nephrotic syndrome, severe illness leading to falsely low TT4/TT3
• Feedback from enough circulating T4, T3 in the blood causes decrease in TSH in the pituitary |
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Term
| Thyroid Function Diagnostic Tests |
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Definition
• TSH is the best test for assessing thyroid function initially
• Free/total T4
• Free/total T3
• Free T4 by equilibrium dialysis—most reliable measure but is a send out
• Use free T4/T3 since total levels are affected by TBG levels
• Thyroglobulin (Tg)—nonspecific use in hypothyroidism. Also used in monitoring after papillary/follicular thyroid cancer s/p thyroidectomy
• Thyroid peroxidase Abs (TPO abs)— positive for Hashimoto’s thyroiditis
• Thyroid stimulating immunoglobulins (TSI)—positive in Graves’ disease
• Calcitonin—positive with medullary thyroid CA; should be checked in all patients with a thyroid nodule
• Thyroid uptake—is the percentage of a small oral dose of I-131 retained by the thyroid after 24 hrs. Low in thyroiditis and high in Graves’ disease
• Thyroid scan—determine the functionality of thyroid nodules. Cold is hypofunctioning and hot is hyperfunctioning. Almost all thyroid CA is cold. All cold nodules need to be biopsied. Hot nodules are almost always benign.
• Thyroid ultrasound—evaluate thyroid nodules or goiter. All patients with hyperthyroidism should have an ultrasound since they have a higher incidence of thyroid CA
• FNA (fine needle aspiration) |
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Term
| Effect of Medications on TFTs |
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Definition
• Steroids/dopamine lower TSH.
• Iodine-containing drugs (amiodarone, contrast) lower TSH.
• Lithium inhibits release of T4/T3, increasing TSH.
• Androgens cause decreased TBG and thus decreased TT4/TT3 levels.
• Estrogens/pregnancy increase TBG and thus increased TT4/TT3 levels. |
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Term
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Definition
• In early pregnancy, increase in TBG causes transient increase in TT4 levels leading to lower TSH because beta subunit of hCG has 85% homology to TSH receptor.
- This low TSH is normal and should not be mistakenly treated with anti-thyroid hormones!
• Pregnant patients with pre-existing hypothyroidism should be treated to a high normal FT4.
• Pregnant patients with pre-existing hyperthyroidism need PTU in the first trimester. 2010 guidelines state Tapazole is ok in 2nd and 3rd trimesters.
- RAI is contraindicated |
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Term
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Definition
• ChangesinTFTsfromnon-thyroidalillnesses and starvation
• TSH, FT4 levels unchanged; TT3/FT3 decrease as a result of reduced T4 to T3 conversion
• Howtotellapartfromhypothyroidism:T3is decreased more than T4 and vice versa in hypothyroidism
• Can also check rT3, and this will be normal to high in euthyroid sick
• Takehomepoint:thisisnotathyroiddisease,so it does not need to be treated!! |
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Term
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Definition
• Most common cause in the U.S. is Hashimoto’s thyroiditis (positive FHx)
• Second most common cause is RAI-induced
• Most common cause worldwide is iodine deficiency
• Secondary (central) hypothyroidism
• Post-surgical or post-radioactive iodine—iatrogenic
• More common in women (2%) vs. men (0.1%) |
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Term
| Hypothyroidism Clinical Findings |
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Definition
• Facial/periorbital puffiness
• Bradycardia
• Constipation
• Weight gain
• Delayed tendon reflexes
• Memory loss
• Carpal tunnel syndrome
• Hypothermia
• Hypoventilation
• Dry skin
• Brittle nails
• Hair loss/coarse hair
• Diastolic HTN |
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Term
| Hypothyroidism Signs and Symptoms |
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Definition
• Cold intolerance • Weight gain
• Dry skin
• Hair loss
• Brittle nails
• Constipation
• LE edema
• Fatigue
• Excessive sleeping
• Decreased appetite
• Decreased libido
• Menorrhagia
• Hoarseness
• Myalgias/arthralgias
• Depression |
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Term
| Hypothyroidism Lab Tests/Imaging |
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Definition
• TSH >20
• FreeT4low
• Total/freeT3low
• PositiveTPO/thyroglobulinAbs
• Hypercholesteremia
• Anemia
• Lowtestosteronelevels(men)
• EKG—bradycardia, low voltage
• Pleural effusion in severe cases
• Thyroid US only if nodules/goiter felt on exam |
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Term
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Definition
| So, this is a graphic representation of what happens when-- so the TSH is first to change. That's why a lot of primary care providers will just check the TSH when they're screening somebody. And then the T4 will go, and then the T3 will be kind of slower and later to change. |
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Term
| Hypothyroidism Complications |
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Definition
• Myxedema/myxedema coma (rare)
• **Decrease in cardiac output and cardiac contractility, leading to HF
• Hypercholesteremia
• Diastolic HTN
• Pericardial effusions from edema |
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Term
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Definition
• Rarely seen
• Uncompensated form of prolonged hypothyroidism
• Oftenprecipitatedbysystemicillness
• S&S:six“hypos”:hypomentia,hypothermia, hypotension, hyponatremia, hypoglycemia, and hypoventilation
• Treatment: 50–100mcg IV LT4 q8 then qd and hydrocortisone 50mg IV q8 to prevent adrenal failure with high dose thyroid hormone replacement |
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Term
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Definition
Levothyroxine is the number 2 most prescribed medication in the U.S. in 2017!
-
• Synthroid/Levoxyl/levothyroxine: T4
• Cytomel: T3 and very potent!!
• Do not switch brands once the patient is on one
• Brand is best because the generic levothyroxine varies in potency per pill by 20%
• For young, healthy adults, start with 50–100mcg qd
• Full replacement dose is 1.6u/kg
• In elderly or those with underlying cardiac conditions, start low and go slow to prevent AFib! Start 25–50mcg qd/alternate doses
• Titrate q6–8 weeks by 25mcg until TSH is between 1.0–2.0 and FT4 is normal—patients feel best at these levels! Cardiac patients’ TSH should be around 4.0
• Should be taken on an empty stomach (30 min before meals), not with iron, calcium, PPIs, since these inhibit absorption in the stomach
• SE: Tachycardia (over-replacement), osteoporosis, AFib |
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Term
Treatment for Hypothyroidism
If a patient’s TSH is not improving with thyroid hormone replacement: |
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Definition
• Consider noncompliance or taking it with food/iron/calcium
• Gaining/losing weight which will cause the need for the dose to change
• Switch from generic to brand or try different formulation; e.g., Armour, Tirosint
• Malabsorption in the stomach by chronic diarrhea/celiac disease |
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Term
| Subclinical Hypothyroidism |
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Definition
• TSH 5-20, FT4, and TT3/FT3 normal or low-normal
• Called mild thyroid failure
• More common than over-hypothyroidism
• S&S compatible with hypothyroidism
• Usually have positive Abs and as Abs increase, TSH will increase causing the disease to progress
• Treat with thyroid hormone to TSH 1.0-2.0 |
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Term
| A 45-year-old female presents c/o fatigue, 30-pound weight gain despite dieting, constipation, and menorrhagia. On PE, the thyroid is not palpable, the skin is cool and dry, heart sounds are quiet, and the pulse is 50. Rectal and pelvic exams are within normal limits. Stool is negative for occult blood. The clinical findings suggest? |
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Definition
Clinical findings suggest-- so you guys can think about this. What other features of the history would you want to know? What other findings on physical exam? Pathogenesis. Lab tests. What are the most possible causes of the condition? And other conditions that might be associated with this disorder.
So something to just kind of thing about and answer when you get a chance. Thank you. |
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Term
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Definition
• Excess thyroid hormone
• Elevated T3/T4 and low TSH
• Graves’ disease most common • TT3>FT4
• Toxic multinodular goiter
• Toxic uninodular goiter
• Subacute thyroiditis
• Painless thyroiditis
• Medication-induced (iodine supplements or over-replacement of thyroid hormone) |
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Term
| Hyperthyroidism Laboratory Tests/Imaging |
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Definition
• TSH low or undetectable
• FT4/TT3/FT3 high
• Positive TSI
• Elevated LFTs/Alk Phos
• Thyroid US–goiter or nodule
- Patients with Graves’ have a higher chance of having thyroid CA
• Thyroid uptake high |
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Term
| Hyperthyroidism PE findings |
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Definition
• Hyperreflexia
• Lid lag, stare
• Tachycardia/AFib
• Warm, moist skin and hands
• Palmar erythema
• Hair loss
• Thyroid bruit
• Proximal muscle weakness
• Weight loss
• Systolic HTN
• Pretibial myxedema/dermatopathy (plaque-like thickening of the skin over the shins due to accumulation of glycosaminoglycans in the dermis) |
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Term
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Definition
• Heart palpitations
• Ophthalmopathy/proptosis
• Diarrhea
• Jitteriness/shakiness
• Weight loss
• Eye pain/changes
• Anxiety
• Heat intolerance/sweatiness
• Oligomenorrhea/amenorrhea
• Increased appetite
• Insomnia
• Difficulty concentrating
• Emotional irritability |
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Term
| Hyperthyroidism Complications |
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Definition
• Atrial fibrillation
• Heart failure
• Systolic HTN
• Osteoporosis
• Increased risk for papillary thyroid cancer —only if adenoma is present |
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Term
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Definition
• Autoimmune disorder in which Abs directed against TSH receptor result in continuous stimulation of the thyroid gland to produce and secrete T4/T3
• Often positive FHx
• Women (2%) > men (0.2%)
• Present with more profound symptoms
• Three hallmark physical exam findings: thyroid bruit, ophthalmopathy, and pretibial myxedema/dermatopathy
• Positive TSI, TT3>FT4
• Diffuse symmetric goiter
• Can be difficult to treat; usually need permanent therapy
• Can be lifelong problem if not properly treated |
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Term
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Definition
• Life-threatening condition characterized by an exaggeration of the manifestations of hyperthyroidism
• Patients usually have underlying and undiagnosed hyperthyroidism and superimposed precipitating event such as thyroid surgery, other surgery, infection, trauma
• S&S:fever>102,tachycardia,N/V,abdominal pain, psychosis, cardiac arrhythmias
• TSH undetectable, T3/T4 elevated
• Treat with:
- PTU 200mg q4/methimazole 20mg q4
- SSKI 5 drops q8/Lugol’s solution 10 drops q8
- Metoprolol 5–10mg IV q2–4
- Dexamethasone 2mg q6/HC 100mg IV q8 for circulation support
- IVF and treat underlying condition |
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Term
| Treatment of Hyperthyroidism |
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Definition
1. Anti-thyroid medications/thionamides
- Methimazole/Tapazole
• Inhibits thyroid hormone synthesis via thyroid peroxidase
• Dosed 5mg–40mg QD
• Titrate according to TFTs qmonth. Decrease when FT4/FT3 are normal/starting to turn hypo
• Goal is to cure mild hyperthyroidism by gradually tapering over 1–2 years
• Usually doesn’t work with Graves’ disease because this is more severe
- PTU/propylthiouracil
• Inhibits peripheral conversion of T4 to T3 by Type 1 deiodinase
• Use in pregnancy/lactation
• Dosed 100–400mg tid-qid
- SideeffectsofTapazole/PTUarerash/fever/sore throat from allergy or agranulocytosis. Also hepatotoxicity, so LFTs must be checked
2. Beta blocker
• Helps with symptoms of tachycardia/anxiety/HTN
• Start with atenolol/metoprolol/propranolol
3. Definitive/permanent therapy with:
- RAI (radioactive iodine)
• Best choice for Graves’ disease
• Cannot use in pregnancy/lactation
• Dosed in pill form 5–15mCI. Determined by nuclear medicine
• Pre-treat patients with Tapazole until FT4 and FT3 are normal (patient is “cooled off”), then dose RAI. Tapazole to be stopped 1 week prior
• Follow up with TFTs 4–6 weeks after RAI. If overdosed, can become hypothyroid—more than 50% develop hypo. Can act up to 1 year, so continue to follow closely for 1 year
• With small doses, low risk for developing secondary CA |
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Term
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Definition
• UseifpatientrefusedRAIorside effects/refractory to anti-thyroid drugs
• Inpreparationforsurgery,giveTapazoleuntil euthyroid. Give SSKI (supersaturated potassium iodine) 40–80mg (1–2 drops in OJ) bid 1–2 weeks prior to block the thyroid. Stop this med regimen post-op.
• Willneedtostartonthyroidhormone replacement therapy |
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Term
| Pregnancy and Hyperthyroidism |
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Definition
• Use caution when diagnosing since TSH levels are low in the first trimester, so always check FT4 and TT3 with TSH.
• Can only use PTU because it crosses the placenta less than Tapazole.
• Can lead to spontaneous abortion, premature labor, preeclampsia if not treated appropriately. |
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Term
| Toxic Multinodular Goiter |
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Definition
• Second most common cause of hyperthyroidism
• Area/nodule of autonomous function within a MNG
• Nuclear scan is diagnostic and will show a “hot” over-functioning nodule
• Need to make sure it is not cancer before treating. Most hot nodules are benign but not all! Do US and/or FNA if there are any concerning features
• Causes low TSH/mild hyperthyroidism and symptoms
• Treat with anti-thyroid medication if mild or if patient does not want permanent treatment, although these are less likely to spontaneously resolve
• Most need RAI or surgery if causing compression |
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Term
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Definition
• Same as multinodular goiter but just one nodule
• Autonomously functioning nodule that is hot on nuclear medicine scan
• Need to make sure it is not cancer before treating. Most hot nodules are benign but not all! Do US and/or FNA if there are any concerning features
• LowTSHandhyperthyroidsymptoms
• Treat with Tapazole/PTU temporarily but then will need permanent treatment with RAI |
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Term
|
Definition
• A diverse group of disorders characterized by some form of thyroid inflammation
• Painless thyroiditis
• Post-partum thyroiditis
• Subacute thyroiditis
• Infectious thyroiditis |
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Term
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Definition
• Most common: 1–5% of cases of hyperthyroidism
• Considered a variant form of chronic autoimmune thyroiditis (Hashimoto’s), suggesting that it is part of the spectrum of thyroid autoimmune disease
• It is characterized by a transient hyperthyroid phase from follicular damage and release of stored hormone followed by a permanent or transient hypothyroid phase then recovery to euthyroid state
• TFTs change depending on the stage, but are usually not severe
• Permanent hypothyroidism can result in up to 20–30% of patients!
• Hyperthyroid phase usually lasts 2–8 weeks
• RAI uptake is diagnostic at <5%
• It does not have features of Graves’—little or no thyroid enlargement, and no Graves’ ophthalmopathy or pretibial myxedema
• Do not treat with anti-thyroid medications unless the patient has underlying heart disease/AFib or if the TFTs are dramatically abnormal, and then can treat with close follow-up
• Cholestyramine 2G bid, powder form. Helps to bind thyroid hormone in the gut
• BB (metoprolol/atenolol) for symptoms
• Thyroid hormone replacement if permanently hypothyroid |
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Term
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Definition
• Occurs in 12 month postpartum period in up to 8% of women because maternal immune system is suppressed during pregnancy and rebounds after delivery
• Patients at higher risk and need to be screened at 3 and 6 months:
- Type 1 diabetes mellitus
- A history of postpartum thyroiditis after a previous pregnancy
- A history of high serum antithyroid peroxidase antibody concentrations prior to pregnancy
• Follows the same course as painless thyroiditis
• Repeat TFTs to assess for spontaneous improvement
• Treatment for symptoms only if necessary and likely only temporarily —same as painless
• Predisposition to getting hypothyroidism later in life, so should get regular at least yearly TFTs |
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Term
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Definition
• Usually viral cause (URI)
• The patient undergoes four stages:
1. Painful unilateral/bilateral thyroid and has symptoms of fever, malaise, fatigue, and thyrotoxicosis
2. Transitory euthyroid period (weeks)
3. Hypothyroidism as the gland repairs itself
4. Euthyroid again permanently
• Treat with prednisone 20mg x 5 days |
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Term
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Definition
• Rare—acute or chronic
• Patients at risk are immunosuppressed, elderly, untreated underlying thyroid disease
• Acute illness—fever, chills, dysphagia, anterior neck pain, swelling, tender, TFTs usually normal
• Treatment: antibiotics and drainage of abscess if seen on US |
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Term
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Definition
- Caused by interferon-alfa, interleukin-2, amiodarone, lithium, or a tyrosine kinase inhibitor
- Usually occurs on patient with underlying autoimmune thyroiditis
• Interferon—usually painless thyroiditis picture
• Amiodarone—hyper or hypothyroidism
• Lithium – painless thyroiditis or hyper
• TKIs and checkpoint inhibitors— (Keytruda/Opdivo)—hyper or hypo |
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Term
| A 25-year-old AAF presents with a complaint of rapid weight loss despite a voracious appetite. PE reveals tachycardia (110 at rest), fine moist skin, symmetrically enlarged thyroid gland, mild bilateral quad muscle weakness, and a fine tremor. These findings strongly suggest? |
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Definition
• What other features of the history should be elicited?
• Other PE findings?
• Serum TSH and FT4 levels are obtained. What results should be anticipated?
• What are the possible causes for the patient’s condition?
• What is the most common cause of this patient’s condition and what is the pathogenesis?
• What is the pathogenesis of this patient’s tachycardia, weight loss, skin changes, goiter, and muscle weakness? |
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Term
| Euthyroid (Nontoxic) Goiter |
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Definition
• Thyroid enlargement with normal thyroid function. Affects more women than men
• Hashimoto’s
- Doesn’t always lead to hypothyroidism and can cause a goiter.
Always positive TPO Abs
• Iodine deficiency
• On PE, smooth, symmetrically enlarged goiter
• Assess for compressive symptoms—dysphagia, dyspnea, or neck pain
• If positive compressive symptoms, hemi-thyroidectomy; otherwise can monitor with serial US |
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Term
|
Definition
• Can be toxic (hyperthyroid) or nontoxic
• Also usually from Hashimoto’s—Ab destruction and inflammation of the gland
• Thyroid US to assess size/characteristics of nodules and thyroid scan to determine if any functioning nodules
• Risk of malignancy is comparable to incidental thyroid carcinoma
• FNA biopsy if cold nodules and >1cm or one dominant nodule
• Hot nodule can only be treated with RAI after patient becomes euthyroid |
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Term
|
Definition
• Prevalence increases with age. On autopsy in 90-year-olds, it is 60%
• DDx: benign adenoma, carcinoma, cyst, lymphoma/sarcoma, metastatic CA
• Most discovered incidentally from a family member, during physical exam, or on CT/MRI
• Riskincreasesifage<20,presenceofcervical lymphadenopathy, history of radiation to head/neck (Chernobyl), especially in childhood, FHx of medullary CA, FHx of MEN syndromes |
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Term
| Evaluation of Thyroid Nodule |
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Definition
• TSH,FT4,TT3,Tg/TPOAbs
• Calcitonin to r/o medullary CA
• Ifhypothyroidoreuthyroid,thyroidUSisnext step
- Characteristics that indicate malignancy: >1cm, hypoechoic, absence of halo sign, irregular margins, calcifications, increased blood flow
• FNAbiopsy
- Biopsy if >1cm
- If <1cm, follow with serial US q3–6 months
• If hyperthyroid,thyroid scan to determine if it is toxic nodule
- Hot nodule—most often benign and can be watched
- Cold nodule—most often malignant
• Warmnodules—maybemalignant.Theyare really cold nodules that appear to concentrate tracer because they are invested by normal thyroid tissue. Must biopsy...
• When in doubt, biopsy! |
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Term
|
Definition
• Most (95%) of all thyroid nodules are benign adenomas
• Take up iodine and synthesize thyroglobulin and growth is stimulated from TSH
• Differentiated (arising from the thyroid follicle) carcinomas are most common—papillary and follicular
• Medullary
• Anaplastic (de-differentiated) |
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Term
| Bethesda Classification of FNA |
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Definition
• Benign: no treatment; just follow with yearly US.If increases in diameter size >20%, re-FNA
• Indeterminate aka follicular lesion/ atypia of undetermined significance (AUS): 10–40% chance of malignancy. Re-FNA or refer for hemi- thyroidectomy
• Suspicious:50–75% chance of malignancy and need surgery for hemi-thyroidectomy
• Malignant:surgery
• Non diagnostic: cytologically inadequate. Repeat FNA in 4–6 weeks |
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Term
|
Definition
• Most common 50–70%
• Slow growing
• Multifocal and cervical most often
- Presence in lymph nodes does not increase mortality but does increase likelihood of recurrence
• TFTs are usually normal
• FNA may be suspicious/indeterminate or malignant |
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Term
| Treatment of Papillary thyroid cancer |
|
Definition
• Thyroidectomy with cervical and mediastinal lymph node removal
- Risks: hypoparathyroidism, recurrent laryngeal nerve damage
• I-131 (RAI) therapy: 100–200mCI to eradicate all remaining thyroid tissue
- Best taken up by thyroid cells when TSH is >30
- Side effects: sialadenitis, nausea, fatigue, neck pain, increased risk for infection, dry mucosa
• Thyroid hormone replacement with suppression of TSH to 0.1-0.5
• Follow with serial thyroglobulins (should be undetectable both unstimulated and stimulated with high TSH), thyroid US, MRI, PET scan (to assess for de-differentiation) |
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Term
| Recurrence of Papillary thyroid cancer |
|
Definition
• Treatment is controversial.
• Suppressed thyroglobulin <10 that is stable and not increasing is probably residual disease. Need to continue to be followed closely.
• AnydetectableorincreasingTgshouldbe investigated and tried to be found—MRI, CT, PET, whole body scans, US.
• If found, should be removed surgically.
• Repeat dose of RAI only as a last resort, since risk of secondary cancers increases with amount given. |
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Term
| Follicular thyroid cancer |
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Definition
• 10–15% of all cancer
• Can be more aggressive than papillary and can metastasize to lung/bone
• Treated and managed the same as papillary |
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Term
|
Definition
• 1–2% of cancer
• Sporadic vs. hereditary (MEN syndromes)
• Arises from parafollicular cells or C-cells
• C-cells function to inhibit release of calcium from the bone into the serum
• Very elevated serum calcitonin level in presence of thyroid nodule
• Treatment is difficult. RAI does not work. Need thyroidectomy with lymph node dissection
• Screen family members for RET protooncogene
• Thyroid hormone replacement but not to suppressive levels. Follow calcitonin and CEA levels |
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Term
| Anaplastic thyroid cancer |
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Definition
• Rare
• One of the most aggressive and resistant forms of human cancer
• Giant cell, spindle cell, mixed spindle-giant cell, and small cell
• Elderly
• Dyspnea, dysphagia, hoarseness, pain
• Thyroidectomy, EBR, chemo
• Prognosis is 6–8 months |
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