Thyroid Flashcards
The thyroid combines _ and _ to produce thyroid hormones
The thyroid combines iodine and tyrosine to produce thyroid hormones
Symptoms of increased metabolic activity, such as heat intolerance, sweating, insomnia, weight loss, palpitations, anxiety, and diarrhea are all suggestive of _
Symptoms of increased metabolic activity, such as heat intolerance, sweating, insomnia, weight loss, palpitations, anxiety, and diarrhea are all suggestive of hyperthyroidism
The bilateral recurrent laryngeal nerves branch off of the bilateral vagus nerves to innervate all intrinsic muscles of the larynx aside from the _ muscle
The bilateral recurrent laryngeal nerves branch off of the bilateral vagus nerves to innervate all intrinsic muscles of the larynx aside from the cricothyroid muscle
The thyroid is a butterfly gland anterior to the trachea and inferior to the _ cartilage
The thyroid is a butterfly gland anterior to the trachea and inferior to the cricoid cartilage
The superior thyroid artery is a branch off of the _
The superior thyroid artery is a branch off of the external carotid artery
* Brachiocephalic –> left common carotid –> left external carotid –> left superior thyroid artery
The inferior thyroid arteries branch off of the _
The inferior thyroid arteries branch off of the subclavian arteries
The nerve that runs closest to the thyroid is the _
The nerve that runs closest to the thyroid is the recurrent laryngeal nerve
The recurrent laryngeal nerve is a branch of the _ nerve; it runs near the (inferior/superior) thyroid artery
The recurrent laryngeal nerve is a branch of the vagus; it runs near the inferior thyroid artery
Damage to the recurrent laryngeal nerve (from thyroidectomy) may result in _ or _
Damage to the recurrent laryngeal nerve (from thyroidectomy) may result in hoarseness or dysphagia
The thyroid gland produces both T3 and T4, however it produces more _
The thyroid gland produces both T3 and T4, however it produces more T4
* T4 gets converted to T3 which is more biologically active
Iodine deficiency will manifest as a _
Iodine deficiency will manifest as a goiter
* The thyroid enlarges, looking for more iodine
T3 is the regulator of _
T3 is the regulator of metabolism, temperature, weight, muscle strength, nervous system
(Hyperthyroidism/Hypothyroidism) is associated with gynecomastia or abnormal uterine bleeding
Hyperthyroidism is associated with gynecomastia or abnormal uterine bleeding
* Thyroid hormones increase sex hormone binding globulin –> decreases free testosterone –> promotes aromatization of androgens –> estrogens
* Note that menstrual irregularities are associated with both hyper and hypothyroidism
T3 and T4 synthesis occurs in the _
T3 and T4 synthesis occurs in the thyroid follicles
T4 gets converted to T3 _ where?
T4 gets converted to T3 in the periphery
* Most of this happens in the liver
Iodine gets organified and coupled to _ to make T4
Iodine gets organified and coupled to 2 Diiodotyrosine (DIT) to make T4
Iodine gets organified and coupled to _ to make T3
Iodine gets organified and coupled to 1 DIT + 1 monoiodotyrosine (MIT) to make T3
The first step of thyroid synthesis is the uptake of _ into follicular cells
The first step of thyroid synthesis is the uptake of iodide (I-) into follicular cells
After the uptake of iodide the iodide goes through _ and _
After the uptake of iodide the iodide goes through oxidation and organification
The enzyme responsible for oxidation, organification, and coupling is _
The enzyme responsible for oxidation, organification, and coupling is thyroid peroxidase
Thyroid peroxidase (TPO) is active in the _
Thyroid peroxidase (TPO) is active in the colloid of the thyroid
The thyroid hormone substrate which is formed by tyrosine + iodine is called _ ; it later gets coupled to MIT and DIT and then cleaved to release T3 and T4
The thyroid hormone substrate which is formed by tyrosine + iodine is called thyroglobulin ; it later gets coupled to MIT and DIT and then cleaved to release T3 and T4
_ binds T3 and T4 in the serum to prevent its destruction
Thyroid binding globulin binds T3 and T4 in the serum to prevent its destruction
Thyroid binding globulin is produced by the _
Thyroid binding globulin is produced by the liver
_ converts T4 –> T3 in the peripheral tissues
5’ Deiodinase converts T4 –> T3 in the peripheral tissues
When iodine administration inhibits T3 and T4 synthesis and causes hypothyroidism, we call this _
When iodine administration inhibits T3 and T4 synthesis and causes hypothyroidism, we call this Wolff-Chaikoff effect
When iodine adminstration causes uncontrolled T3 and T4 synthesis, we call this _
When iodine adminstration causes uncontrolled T3 and T4 synthesis, we call this Jod-Basedow phenomenon
In the Wolff-Chaikoff effect, the administration of iodine inhibits thyroid hormone synthesis for days via _ mechanism
In the Wolff-Chaikoff effect, the administration of iodine inhibits thyroid hormone synthesis for days via formation of iodopeptides –> inhibition of TPO synthesis
_ can be given for treatment of acute radiation exposure; this takes advantage of the _ phenomenon
Potassium iodide can be given for treatment of acute radiation exposure; this takes advantage of the Wolff-Chaikoff effect
The Jod Basedow phenomenon is most likely to occur in patients with _
The Jod Basedow phenomenon is most likely to occur in patients with dysregulated thyroid hormone synthesis
* Ex: patients with Graves, toxic multinodular goiter, thyroid adenoma
* These patients already have hyperthyroidism; when given iodine the synthesis of T3 and T4 is out of control
Propylthiouracil is an antithyroid medication that works via _
Propylthiouracil (PTU) is an antithyroid medication that works via inhibition of thyroid peroxidase
* Pro-pyl-thio-uracil
Side effects of Propylthiouracil (PTU) include:
Side effects of Propylthiouracil (PTU) include:
* Agranulocytosis
* Aplastic anemia
* Hepatotoxicity
Methimazole is an antithyroid medication that works via _
Methimazole is an antithyroid medication that works via inhibition of thyroid peroxidase
Methimazole side effects include:
Methimazole side effects include:
* Aplasia cutis (first trimester)
* Present in breast milk
_ , _ , _ , and _ are all 5’ Deiodinase inhibitors that inhibit the conversion of T4 –> T3 in the peripheral tissues
Glucocorticoids , beta blockers , PTU , and amiodarone are all 5’ Deiodinase inhibitors that inhibit the conversion of T4 –> T3 in the peripheral tissues
How does lithium affect the thyroid?
Lithium inhibits iodide uptake & TPO & T3/T4 release
* It can cause hypothyroidism or hyperthyroidism
Perchlorate/Pertechnetate is an antithyroid medication that _
Perchlorate/Pertechnetate is an antithyroid medication that inhibits iodine uptake
Graves disease is caused by _
Graves disease is caused by thyroid stimulating IgG which binds to TSH receptors –> T3, T4
Graves disease is a type _ hypersensitivity reaction
Graves disease is a Type II hypersensitivity reaction
Graves disease is associated with _ genetic markers
Graves disease is associated with HLA-DR3, HLA-B8
Graves disease is classically associated with _ eye finding
Graves disease is classically associated with exophthalmos
Explain the pathogenesis of exophthalmos
- T cell activation
- Lymphocyte infiltration into retro-orbital space
- Increased cytokines (TNF-a, INF-gamma)
- Increased fibroblast secretion of GAGs
- Muscle inflammation, osmotic muscle swelling
Graves: tall, crowded columnar follicular epithelial cells, scalloping
_ is the most common cause of hyperthyroidism in the US
Graves is the most common cause of hyperthyroidism in the US
* Very common in females 20-40
Graves disease may present with unique sx such as _ , _ and exophthalmos
Graves disease may present with unique sx such as goiter , pretbial myxedema and exophthalmos
Pretibial myxedema in graves disease is caused by _
Pretibial myxedema in graves disease is caused by activation of fibroblasts that deposit extra collagen
* Non-pitting edema
* Redness
Graves disease is associated with:
_ T3
_ T4
_ TSH
Graves disease is associated with:
High T3
High T4
Low TSH
In addition to normal thyroid labs, graves disease may be diagnosed via the presence of _
In addition to normal thyroid labs, graves disease may be diagnosed via the presence of anti-TSH receptor antibodies
Graves disease will present with _ on scintigraphy
Graves disease will present with diffuse uptake on scintigraphy
In graves disease, lipid panel may show _ and CBC may show _
In graves disease, lipid panel may show low cholesterol, low TGs and CBC may show normocytic anemia
_ is an uncommon, life-threatening complication of untreated hyperthyroidism that is usually brought on by acute stress
Thyroid storm is an uncommon, life-threatening complication of untreated hyperthyroidism that is usually brought on by acute stress
* Agitation, fever, delirium, coma, diarrhea, tachyarrhythmia
Treatment for thyroid storm:
Treatment for thyroid storm:
1. Propranolol (beta blockers)
2. Prophylthiouracil
3. Prednisolone (steroids)
4. Potassium iodide
A baby born to a mother with graves disease is at risk of _
A baby born to a mother with graves disease is at risk of fetal hyperthyroidism
* Thyroid stimulating immunoglobulin can cross the placenta and cause hyperthyroidism in utero
* Predisposes them to low birth weight, prematurity, death
A pregnant woman with Graves disease should be medically managed with _ in the first trimester and _ after the first trimester
A pregnant woman with Graves disease should be medically managed with PTU in the first trimester and methimazole after the first trimester
Acute sympathetic symptoms of hyperthyroidism may be managed with _
Acute sympathetic symptoms of hyperthyroidism may be managed with propranolol (for palpitations, muscle weakness, etc)
Toxic multinodular goiter is caused by _
Toxic multinodular goiter is caused by focal patches of hyperfunctioning follicular cells that work independently of TSH
* TSH is still low due to high T3,T4 but follicular cells continue to spit out thyroid hormone
Toxic multinodular goiter can be diagnosed via:
_ TSH
_ T3
_ T4
Toxic multinodular goiter can be diagnosed via:
Low TSH
High T3
High T4
The most common cause of toxic multinodular goiter is _
The most common cause of toxic multinodular goiter is TSH receptor mutation
Hyperthyroidism caused by TSH receptor mutation is likely to be associated with _ type goiter
Hyperthyroidism caused by TSH receptor mutation is likely to be associated with goiter with multiple nodules (not smooth)
Name three things that might be on your ddx for goiter
Name three things that might be on your ddx for goiter:
1. Iodine deficiency
2. Graves
3. Toxic multinodular goiter
Toxic multinodular goiter will show up as _ on thyroid scintigraphy
Toxic multinodular goiter will show up as “hot” nodules with increased iodine uptake on thyroid scintigraphy
Three management options for toxic multinodular goiter:
Three management options for toxic multinodular goiter:
1. Radioactive iodine ablation
2. Surgical removal
3. Thionamides
Extrinsic thyroid ingestion will show the following labs:
_ T3
_ T4
_ TSH
_ Thyroglobulin
_ 24 hour radioiodine uptake
Extrinsic thyroid ingestion will show the following labs:
High T3
High T4
Low TSH
Low/Normal Thyroglobulin
Low/Undetectable 24 hour radioiodine uptake
Two additional findings may help to differentiate an extrinsic ingestion of thyroid hormone, _ and _
Two additional findings may help to differentiate an extrinsic ingestion of thyroid hormone, low thyroglobulin levels and low 24-hour radioiodine uptake
Amiodarone is an anti-arrythmic drug that can cause hyper or hypothyroidism due to it containing _
Amiodarone is an anti-arrythmic drug that can cause hyper or hypothyroidism due to it containing iodine
* Jod Basedow: autonomous thyroid hormone synthesis
* Wolff-Chaikoff: hypothyroid state
In general, thyroiditis causes (hyper/hypo) thyroidism
In general, thyroididis causes hypothyroidism but often after a transient state of hyperthyroidism
Pregnancy may lead to a _ (hyper/hypo) thyroidism
Pregnancy may lead to a clinically insignificant hyperthyroidism
Increased estrogen during pregnancy causes an increase in _ , causing its thyroid effects
Increased estrogen during pregnancy causes an increase in thyroid binding globulin
* Increased circulating T3,T4 bound to TBG
* Free hormone levels are unchanged
* Not clinically significant (no sx)
Severe hypothyroidism may lead to _
Severe hypothyroidism may lead to myxedema coma
* AMS
* Hypothermia
* Slowing/Failure of multiple organs
The most common cause of hypothyroidism in idodine sufficient countries is _
The most common cause of hypothyroidism in idodine sufficient countries is Hashimoto’s
Hashimoto’s thyroiditis is caused by _
Hashimoto’s thyroiditis is caused by auto-antibodies against thyroid peroxidase (TPO) or thyroglobulin
Hashimoto’s involves two HSR, first type _ hypersensitivity reaction, followed by _
Hashimoto’s involves two HSR, first Type IV hypersensitivity reaction, followed by Type II HS
Explain the pathophysiology of Hashimoto’s
Explain the pathophysiology of Hashimoto’s:
1. CD8+ cytotoxic T cells attack the thyroid (Type IV)
2. Release TPO and thyroglobulin
3. Antibody formation (Type II)
4. Futher thyroid destruction
Hashimoto’s thyroditis is associated with _ genetic markers
Hashimoto’s thyroditis is associated with HLA-DR3, HLA-DR5
HLA-B8 is associated with (Graves/Hashimoto’s)
HLA-B8 is associated with Graves
HLA-DR5 is associated with (Graves/Hashimoto’s)
HLA-DR5 is associated with Hashimoto’s
* Both of them are associated with HLA-DR3
A hashimoto thyroid may feel _
A hashimoto thyroid may feel nontender, enlarged, symmetrical, “rubbery”
What is hashitoxicosis?
Hashitoxicosis may occur in the first stage of Hashimoto’s when we have transient hyperthyroidism from the release of lots of T3 and T4
Hashimoto’s labs:
_ T3
_ T4
_ TSH
_ Thyroglobulin
Hashimoto’s labs:
High then Low T3
High then Low T4
Low then High TSH
High then ? Thyroglobulin
Two classical histologic findings in Hashimoto’s thyroiditis are _ and _
Two classical histologic findings in Hashimoto’s thyroiditis are Hurthle cells and lymphoid aggregates with germinal centers
Hashimoto’s is managed with _
Hashimoto’s is managed with levothyroxine
Postpartum thyroiditis is very similar to _
Postpartume thyroiditis is very similar to Hashimoto’s
* Subacute lymphocytic thyroiditis
* Shares the same pathophysiology as Hashimoto’s but brought on by pregnancy, up to one year after delivery
Compare the appearance of the thyroid in someone with Hashimoto’s disease vs Postpartum thyroiditis
Compare the appearance of the thyroid in someone with
Hashimoto’s disease: Thyroid is enlarged, symmetrical and rubbery
Postpartum thyroiditis: Thyroid is normal size and nontender
Compare and contrast the histopathology of Hashimoto’s with postpartum thyroiditis
Hashimoto’s: Lymphoid aggregates with germinal centers and Hurthle cells
Postpartum thyroiditis: Lymphoid aggregates with germinal centers and no Hurthle cells or fibrosis
How do we manage postpartum thyroiditis?
Postpartum thyroiditis is usually self-limiting and no treatment is required
Subacute granulomatous thyroiditis is also called _
Subacute granulomatous thyroiditis is also called De Quervain thyroiditis
Subacute granulomatous thyroiditis is brought on by _
Subacute granulomatous thyroiditis is brought on by viral infection/flu-like illness
* Infection leads to inflammatory damage of the thyroid follicles –> release of T3 and T4
_ is associated with recent illness causing a transient hyperthyroidism followed by hypothyroidism
De Quervain is associated with recent illness causing a transient hyperthyroidism followed by hypothyroidism
Clinical signs of De Quervain thyroiditis include _ and _
Clinical signs of De Quervain thyroiditis include very tender thyroid and jaw pain
What lab findings do we expect with subacute granulomatous thyroiditis
What lab findings do we expect with subacute granulomatous thyroiditis:
Low T3,T4
High TSH
High Thyroglobulin
High ESR
High CRP
De Quervain thyroiditis is associated with _ histology findings
De Quervain thyroiditis is associated with granulomatous inflammation, multinucleated giant cells, foamy histiocytes
How do we manage subacute granulomatous thyroiditis?
It is usually self-limiting and does not require treatment
* If symptomatic consider corticosteroids
Riedel thyroiditis is characterized by _
Riedel thyroiditis is characterized by the replacement of normal thyroid with fibrous tissue
* IgG related systemic disease
* Inflammatory infiltrates
Clinical signs of Riedel thyroiditis:
Clinical signs of Riedel thyroiditis:
* Fixed, rock-like painless goiter
* Dysphagia
* Hoarseness
* Dyspnea
* Hypothyroidism
Riedel will present with _ type goiter
Riedel will present with rock-like painless goiter
Riedel thyroiditis is associated with an increased risk of developing _
Riedel thyroiditis is associated with an increased risk of developing thyroid lymphoma
Riedel will present on histology with _
Riedel will present on histology with fibrous tissue with inflammatory infiltrate
Riedel thyroiditis is managed with _ and _
Riedel thyroiditis is managed with levothyroxine and thyroidectomy
How does iodine deficiency present?
Iodine deficiency presents with hypothyroidism sx, goiter
* More common in developing countries
* Manage via iodine
Congenital hypothyroidism occurs due to _
Congenital hypothyroidism occurs due to Ab-mediated maternal hypothyroidism
* IgG crosses the placenta
In congenital hypothyroidism, _ antibodies cross the placenta and induce fetal thyroid dysgenesis
In congenital hypothyroidism, IgG antibodies cross the placenta and induce fetal thyroid dysgenesis
* The hypothyroidism does not present until after birth
Clinical signs of congenital hypothyroidism include:
Clinical signs of congenital hypothyroidism include: pot-belly, pale, puffy face, protruding umbilicus, protruding tongue, poor brain development, hoarse cry, hypotonia
Congenital hypothyroidism often presents when?
Congenital hypothyroidism often presents weeks to months after birth
* Because maternal T4 crosses the placenta
Radiation destroys thyroid tissue, leaving no functional tissue left to produce T3, T4; to prevent this kind of damage we can administer _
Radiation destroys thyroid tissue, leaving no functional tissue left to produce T3, T4; to prevent this kind of damage we can administer potassium iodide
Euthyroid sick syndrome is caused by _
Euthyroid sick syndrome is caused by a non-thyroidal illness that increases cytokines –> cytokines decrease thyroid hormone production
* This is potentially an adaptive mechanism that allows the body to preserve energy during illness
* It is self resolving
_ and _ are two classic pharmaceutical agents that are known to cause hypothyroidism
Lithium and Amiodarone are two classic pharmaceutical agents that are known to cause hypothyroidism
_ is a benign, solitary growth of the thyroid
Thyroid adenoma is a benign, solitary growth of the thyroid
Thyroid adenomas are associated with (hot/cold) nodules
Thyroid adenomas are associated with cold nodules
* Despite the fact that they are cold, they are benign
A “cold” thyroid nodule means that it _ ; this tends to be (cancerous/non-cancerous)
A “cold” thyroid nodule means that it does not take up radioiodine ; this tends to be cancerous
Thyroid adenomas are associated with (hyperthyroidism/hypothyroidism)
Thyroid adenomas are associated with hyperthyroidism
How do thyroid adenomas normally present?
Thyroid adenomas are associated with hyperthyroidism and thyrotoxicosis; however they are most frequently asymptomatic
Thyroid adenoma presents on histology as _
Thyroid adenoma presents on histology as follicular changes but no capsular or vascular invasion
* Increased variability of the follicle size
The most common form of thyroid cancer is _
The most common form of thyroid cancer is papillary carcinoma
Three risk factors associated with the development of papillary carcinoma
Three risk factors associated with the development of papillary carcinoma:
1. RET/PTC rearrangements
2. BRAF mutations
3. Childhood irradiation
_ test is needed for the diagnosis of papillary carcinoma
Fine needle aspiration is needed for the diagnosis of papillary carcinoma
The most common presentation of papillary carcinoma is _
The most common presentation of papillary carcinoma is asymptomatic
Papillary carcinoma has a _ prognosis and is treated via _
Papillary carcinoma has a very good prognosis and is treated via thyroidectomy
Histopathology of papillary carcinoma is likely to show _ and _
Histopathology of papillary carcinoma is likely to show Orphan Annie nuclei and psammoma bodies
Empty appearing nuclei with central clearing describes the histology of _
Empty appearing nuclei with central clearing describes the histology of papillary carcinoma
Follicular carcinoma is characterized by _
Follicular carcinoma is characterized by invasion of the thyroid capsule and vasculature
Follicular carcinoma is associated with _ spread
Follicular carcinoma is associated with hematogenous spread to the bone and lungs
Follicular carcinoma will present as _ on histology
Follicular carcinoma will present as well-differentiated, uniform follicles and invasion of the thyroid capsule and vasculature on histology
Follicular carcinoma is associated with mutations in _ and _ translocations
Follicular carcinoma is associated with mutations in RAS and PAX8-PPAR-gamma translocations
Follicular carcinoma is associated with _ prognosis and is treated with _
Follicular carcinoma is associated with good prognosis and is treated with thyroidectomy
Medullary carcinoma is derived from _ cells which release _
Medullary carcinoma is derived from parafollicular C cells cells which release calcitonin
Medullary carcinoma is associated with _ mutations as well as _ phenomenon
Medullary carcinoma is associated with RET mutations as well as MEN2A and MEN2B
Medullary carcinoma will present as _ on histology
Medullary carcinoma will present as well-differentiated sheets of cells in amyloid stroma + stains with green birefringence on congo red stain
Medullary carcinoma is treated via _
Medullary carcinoma is treated via thyroidectomy
Anaplastic carcinoma presents with _
Anaplastic carcinoma presents with a rapidly enlarging neck mass, often presents in older patients
Anaplastic carcinoma will present with _ on histology
Anaplastic carcinoma will present with areas of necrosis, hemorrhaging, and giant cells on histology
* Poorly differentiated, associated with a very poor prognosis
* May compress the surrounding structures
_ thyroid neoplasm is most likely to present with dysphagia and dyspnea
Anaplastic carcinoma is most likely to present with dysphagia and dyspnea
Anaplastic carcinoma is associated with _ mutation
Anaplastic carcinoma is associated with TP53 mutation
The thyroid is derived from _ (layer) between the _ and _ pharyngeal pouches near the base of the tongue
The thyroid is derived from endoderm between the second and third pharyngeal pouches near the base of the tongue
The base of the tongue, where the thyroid descends downward from is called the _
The base of the tongue, where the thyroid descends downward from is called the foramen cecum
The thyroid descends (anterior/posterior) to the hyoid bone
The thyroid descends anterior to the hyoid bone
The _ is a structure that connects the thyroid and tongue during caudal migration from the foramen cecum
The thyroglossal duct is a structure that connects the thyroid and tongue during caudal migration from the foramen cecum
The thyroglossal duct obliterates around week _
The thyroglossal duct obliterates around week 8-10
The dorsal wings third pharyngeal pouch becomes the _
The dorsal wings third pharyngeal pouch becomes the inferior parathyroid glands
The dorsal wings fourth pharyngeal pouch becomes the _
The dorsal wings fourth pharyngeal pouch becomes the superior parathyroid glands
The ventral wing of the fourth pharyngeal pouch gives rise to the _
The ventral wing of the fourth pharyngeal pouch gives rise to the parafollicular C cells
Faulty migration or persistence of the thyroglossal duct may give rise to _ or _
Faulty migration or persistence of the thyroglossal duct may give rise to thyroid ectopia or thyroglossal duct cysts
The parathyroids develop from the _ and _ pharyngeal pouches
The parathyroids develop from the third and fourth pharyngeal pouches
Parafollicular cells (C cells) arise from the _ which originates in the _ pouch
Parafollicular cells (C cells) arise from the ultimobranchial body which originates in the fourth pouch
Parafollicular (C cells) secrete _
Parafollicular (C cells) secrete calcitonin
Papillary thyroid carcinoma
Follicular carcinoma
Anaplastic thyroid carcinoma
The right and left lobes of the thyroid are connected via the _
The right and left lobes of the thyroid are connected via the isthmus
Some individuals have a _ , which is just the persistence of thyroid tissue in the inferior segment of the thyroglossal duct
Some individuals have a pyramidal lobe , which is just the persistence of thyroid tissue in the inferior segment of the thyroglossal duct
The parathyroid glands are small glands (the size of a grain of rice) located at the _
The parathyroid glands are small glands (the size of a grain of rice) located at the posterior side of the thyroid
Arrows are pointing to _ cells
C cells (parafollicular cells)
Normal thyroid follicles are lined with _ and filled with _
Normal thyroid follicles are lined with follicular epithelium and filled with colloid
Multinodular goiter pathology may present on histology with _
Multinodular goiter pathology may present on histology with hyperplasia, colloid accumulation, nodule formation
Multinodular goiter:
Left shows hyperplasia, top right shows colloid accumulation, bottom right shows nodule formation
By definition, thyroiditis means _
By definition, thyroiditis means inflammation of the thyroid gland
* This inflammation leads to damage of the follicular cells
* Typically presents as hypothyroidism
The most common cause of hypothyroidisim is _
The most common cause of hypothyroidism is Hashimoto thyroiditis aka chronic lymphocytic thyroiditis
Hurthle cells
_ is a thyroiditis that involves thick bands of fibrosis replacing the normal parenchyma
Reidel thyroiditis is a thyroiditis that involves thick bands of fibrosis replacing the normal parenchyma
* It makes the thyroid feel “woody” and firm
Reidel thyroiditis is an autoimmune condition associated with _ antibody
Reidel thyroiditis is an autoimmune condition associated with IgG4
De Quervain thyroiditis
Subacute granulomatous thyroiditis usually occurs following _ and presents with a _ goiter
Subacute granulomatous thyroiditis usually occurs following acute viral infection and presents with a painful goiter
_ is a benign mass that origintes from the thyroid follicular cells; it is a well circumscribed nodule with a fibrous capsule
Follicular adenoma is a benign mass that origintes from the thyroid follicular cells; it is a well circumscribed nodule with a fibrous capsule
Criteria for diagnosing follicular carcinoma requires that there is _ and _
Criteria for diagnosing follicular carcinoma requires that there is invasion into blood vessels and invasion through the capsule
Follicular nuclei may have _ or _ in papillary thyroid carcinoma
Follicular nuclei may have elongation/overlapping or dispersed chromatin (clearing) in papillary thyroid carcinoma
Psammoma bodies are also associated with _ thyroid neoplasm
Psammoma bodies are also associated with papillary thyroid carcinoma
_ is a highly aggressive thyroid neoplasm that is often large, painful, and infiltrative into the soft tissues of the neck and trachea
Anaplastic thyroid carcinoma is a highly aggressive thyroid neoplasm that is often large, painful, and infiltrative into the soft tissues of the neck and trachea
Anaplastic thyroid carcinoma
_ is a thyroid neoplasm that secretes calcitonin; it is derived from parafollicular C-cells
Medullary thyroid carcinoma is a thyroid neoplasm that secretes calcitonin; it is derived from parafollicular C-cells
25% of medullary thyroid carcinomas are genetically derived, usually from _ oncogene mutations
25% of medullary thyroid carcinomas are genetically derived, usually from RET oncogene mutations
* This includes MEN2A and MEN2B
Medullary thyroid carcinoma will have a _ appearnace
Medullary thyroid carcinoma will have a neuroendocrine appearance with “packets” of uniform round/oval cells
Subclinical hyperthyroidism labs:
Subclinical hyperthyroidism:
Low TSH and TRH. Normal T4 and T3
Subclinical hypothyroidism labs:
Subclinical hypothyroidism labs:
High TSH and TRH. Normal T4 and T3
Overt primary hyperthyroidism labs:
Overt primary hyperthyroidism labs:
Low TSH and TRH. Hight T4 and T3
Overt primary hypothyroidism labs:
Overt primary hypothyroidism labs:
High TSH and TRH. Low T4 and T3
Central (secondary) hypothyroidism labs:
Low TSH, T4 and T3. TRH is typically high as it is caused by a damaged pituitary gland. If there is damage to the hypothalamus, TRH will be low
Central (secondary) hyperthyroidism labs:
Central (secondary) hyperthyroidism labs:
High TSH, T4 and T3. TRH is low as this condition occurs from a pituitary adenoma secreting TSH.
The best lab test for a patient with a thyroid mass is _
The best lab test for a patient with a thyroid mass is TSH
The best imaging for a thyroid mass is _
The best imaging for a thyroid mass is ultrasound
The best functional imaging test for a patient with a thyroid mass is _
The best functional imaging test for a patient with a thyroid mass is radioactive iodine uptake scan
Identify A
A: Normal
Identify B
B: Grave’s disease
Identify C
C: toxic multinodular goiter
Identify D
D: toxic adenoma
Identify E
E: thyroiditis
Name 5 types of thyroiditis
- Lymphocytic thyroiditis (Hashimoto)
- Subacute granulomatous thyroiditis (De Quervain)
- Fibrosing thyroiditis (Riedel)
- Drug induced thyroiditis
- Trauma induced thyroiditis
Name the 6 P’s of congenital hypothyroidism
Name the 6 P’s of congenital hypothyroidism:
1. Pot belly
2. Protruding umbilicus
3. Protruding tongue
4. Pale
5. Puffy
6. Poor brain development
List the most common causes of hypothyroidism in adults:
List the most common causes of hypothyroidism in adults:
* Lymphocytic thyroiditis
* Iodine deficiency
* Thyroidectomy or radiation
* Medications- lithium, amiodarone
What are some other lab abnormalities associated with hypothyroidism?
Hypothyroidism is associated with:
* Elevated cholesterol levels
* Elevated CK
* Hyponatremia
* Type I diabetes- elevated A1C (possible)
We test for an iodine deficiency using _
We test for an iodine deficiency using urine iodine
_ is a T3 replacement option that is less often used because of its shorter half-life
Liothyronine is a T3 replacement option that is less often used because of its shorter half-life
What effect does amiodarone have on thyroid hormone levels?
Amiodarone decreases the peripheral conversion of T4 –> T3
* So may cause decrease in free T3 levels
Estrogens may _ free T3 levels
Estrogens may decrease free T3 levels
Estrogen decreases free T3 levels by increasing _
Estrogen decreases free T3 levels by increasing thyroid binding globulin
Phenobarbital, Carbamazepine, and phenytoin also decrease free T3 levels by _
Phenobarbital, Carbamazepine, and phenytoin also decrease free T3 levels by increasing hepatic metabolism of thyroid hormone
Life threatening hypothyroidism is called _ and results in _ sx
Life threatening hypothyroidism is called myxedema coma –>
* Hypothermia
* Hyponatremia
* Bradycardia
* Hypoglycemia
* Hypoxia
* Hypoventilation
* Diffuse swelling
Treatment for myxedema coma includes _
Treatment for myxedema coma includes levothyroxine, liothyronine, glucocoricoids (IV)
Why are glucocorticoids given in the treatment of myxedema coma?
Patients with myxedema coma may also have an underlying AI
* If thyroid hormone is given before glucocorticoids then cortisol may drop further due to triggering an increase in metabolism
Onycholysis is _
Onycholysis is separation of the nail from the nail bed, sign of hyperthyroidism
(Methimazole/ PTU) has fewer teratogenic effects but _ has less liver toxicity
PTU has fewer teratogenic effects but methimazole has less liver toxicity
Subacute granulomatous thyroditis is associated with a painful goiter and a (hyper/hypo/eu) thyroid state
Subacute granulomatous thyroditis is associated with a painful goiter and a hyper –> hypo –> euthyroid state
* We treat with NSAIDs
Papillary carcinoma is associated with gene mutations _ or _
Papillary carcinoma is associated with gene mutations BRAF or RET
Follicular carcinoma is associated with gene mutations _
Follicular carcinoma is associated with gene mutations RAS
Medullary carcinoma is associated with gene mutations _
Medullary carcinoma is associated with gene mutations RET (and MEN2A and 2B)
Anaplastic carcinoma is associated with gene mutations _ or _
Anaplastic carcinoma is associated with gene mutations p53 or RAS
Hyperactive thyroid nodule
Well differentiated thyroid cancers like follicular carcinoma and papillary carcinoma can be monitored with _ levels
Well differentiated thyroid cancers like follicular carcinoma and papillary carcinoma can be monitored with thyroglobulin levels
Medullary carcinoma should be monitored via _ levels
Medullary carcinoma should be monitored via calcitonin levels
