Thyroid Flashcards
(207 cards)
1
Q
The thyroid combines _ and _ to produce thyroid hormones
A
The thyroid combines iodine and tyrosine to produce thyroid hormones
2
Q
Symptoms of increased metabolic activity, such as heat intolerance, sweating, insomnia, weight loss, palpitations, anxiety, and diarrhea are all suggestive of _
A
Symptoms of increased metabolic activity, such as heat intolerance, sweating, insomnia, weight loss, palpitations, anxiety, and diarrhea are all suggestive of hyperthyroidism
3
Q
The bilateral recurrent laryngeal nerves branch off of the bilateral vagus nerves to innervate all intrinsic muscles of the larynx aside from the _ muscle
A
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
4
Q
The thyroid is a butterfly gland anterior to the trachea and inferior to the _ cartilage
A
The thyroid is a butterfly gland anterior to the trachea and inferior to the cricoid cartilage
5
Q
The superior thyroid artery is a branch off of the _
A
The superior thyroid artery is a branch off of the external carotid artery
* Brachiocephalic –> left common carotid –> left external carotid –> left superior thyroid artery
6
Q
The inferior thyroid arteries branch off of the _
A
The inferior thyroid arteries branch off of the subclavian arteries
7
Q
The nerve that runs closest to the thyroid is the _
A
The nerve that runs closest to the thyroid is the recurrent laryngeal nerve
8
Q
The recurrent laryngeal nerve is a branch of the _ nerve; it runs near the (inferior/superior) thyroid artery
A
The recurrent laryngeal nerve is a branch of the vagus; it runs near the inferior thyroid artery
9
Q
Damage to the recurrent laryngeal nerve (from thyroidectomy) may result in _ or _
A
Damage to the recurrent laryngeal nerve (from thyroidectomy) may result in hoarseness or dysphagia
10
Q
The thyroid gland produces both T3 and T4, however it produces more _
A
The thyroid gland produces both T3 and T4, however it produces more T4
* T4 gets converted to T3 which is more biologically active
11
Q
Iodine deficiency will manifest as a _
A
Iodine deficiency will manifest as a goiter
* The thyroid enlarges, looking for more iodine
12
Q
T3 is the regulator of _
A
T3 is the regulator of metabolism, temperature, weight, muscle strength, nervous system
13
Q
(Hyperthyroidism/Hypothyroidism) is associated with gynecomastia or abnormal uterine bleeding
A
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
14
Q
T3 and T4 synthesis occurs in the _
A
T3 and T4 synthesis occurs in the thyroid follicles
15
Q
T4 gets converted to T3 _ where?
A
T4 gets converted to T3 in the periphery
* Most of this happens in the liver
16
Q
Iodine gets organified and coupled to _ to make T4
A
Iodine gets organified and coupled to 2 Diiodotyrosine (DIT) to make T4
17
Q
Iodine gets organified and coupled to _ to make T3
A
Iodine gets organified and coupled to 1 DIT + 1 monoiodotyrosine (MIT) to make T3
18
Q
The first step of thyroid synthesis is the uptake of _ into follicular cells
A
The first step of thyroid synthesis is the uptake of iodide (I-) into follicular cells
19
Q
After the uptake of iodide the iodide goes through _ and _
A
After the uptake of iodide the iodide goes through oxidation and organification
20
Q
The enzyme responsible for oxidation, organification, and coupling is _
A
The enzyme responsible for oxidation, organification, and coupling is thyroid peroxidase
21
Q
Thyroid peroxidase (TPO) is active in the _
A
Thyroid peroxidase (TPO) is active in the colloid of the thyroid
22
Q
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
A
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
23
Q
_ binds T3 and T4 in the serum to prevent its destruction
A
Thyroid binding globulin binds T3 and T4 in the serum to prevent its destruction
24
Q
Thyroid binding globulin is produced by the _
A
Thyroid binding globulin is produced by the liver
25
_ converts T4 --> T3 in the peripheral tissues
**5' Deiodinase** converts T4 --> T3 in the peripheral tissues
26
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**
27
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**
28
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**
29
_ 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**
30
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
31
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
32
Side effects of Propylthiouracil (PTU) include:
Side effects of Propylthiouracil (PTU) include:
* Agranulocytosis
* Aplastic anemia
* Hepatotoxicity
33
Methimazole is an antithyroid medication that works via _
Methimazole is an antithyroid medication that works via **inhibition of thyroid peroxidase**
34
Methimazole side effects include:
Methimazole side effects include:
* Aplasia cutis (first trimester)
* Present in breast milk
35
_ , _ , _ , 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
36
How does lithium affect the thyroid?
**Lithium** inhibits iodide uptake & TPO & T3/T4 release
* It can cause *hypothyroidism or hyperthyroidism*
37
Perchlorate/Pertechnetate is an antithyroid medication that _
Perchlorate/Pertechnetate is an antithyroid medication that **inhibits iodine uptake**
38
Graves disease is caused by _
Graves disease is caused by **thyroid stimulating IgG** which binds to TSH receptors --> T3, T4
39
Graves disease is a type _ hypersensitivity reaction
Graves disease is a **Type II** hypersensitivity reaction
40
Graves disease is associated with _ genetic markers
Graves disease is associated with **HLA-DR3, HLA-B8**
41
Graves disease is classically associated with _ eye finding
Graves disease is classically associated with **exophthalmos**
42
Explain the pathogenesis of exophthalmos
1. T cell activation
2. Lymphocyte infiltration into retro-orbital space
3. Increased cytokines (TNF-a, INF-gamma)
4. Increased fibroblast secretion of GAGs
5. Muscle inflammation, osmotic muscle swelling
43
Graves: tall, crowded columnar follicular epithelial cells, scalloping
44
_ 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
45
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
46
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
47
Graves disease is associated with:
_ T3
_ T4
_ TSH
Graves disease is associated with:
**High** T3
**High** T4
**Low** TSH
48
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**
49
Graves disease will present with _ on scintigraphy
Graves disease will present with **diffuse uptake** on scintigraphy
50
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**
51
_ 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
52
Treatment for thyroid storm:
Treatment for thyroid storm:
1. **Propranolol** (beta blockers)
2. **Prophylthiouracil**
3. **Prednisolone** (steroids)
4. **Potassium iodide**
53
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
54
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
55
Acute sympathetic symptoms of hyperthyroidism may be managed with _
Acute sympathetic symptoms of hyperthyroidism may be managed with **propranolol** (for palpitations, muscle weakness, etc)
56
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
57
Toxic multinodular goiter can be diagnosed via:
_ TSH
_ T3
_ T4
Toxic multinodular goiter can be diagnosed via:
**Low** TSH
**High** T3
**High** T4
58
The most common cause of toxic multinodular goiter is _
The most common cause of toxic multinodular goiter is **TSH receptor mutation**
59
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)**
60
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
61
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
62
Three management options for toxic multinodular goiter:
Three management options for toxic multinodular goiter:
1. Radioactive iodine ablation
2. Surgical removal
3. Thionamides
63
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
64
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**
65
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
66
In general, thyroiditis causes (hyper/hypo) thyroidism
In general, thyroididis causes **hypothyroidism** but often after a transient state of hyperthyroidism
67
Pregnancy may lead to a _ (hyper/hypo) thyroidism
Pregnancy may lead to a **clinically insignificant hyperthyroidism**
68
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)
69
Severe hypothyroidism may lead to _
Severe hypothyroidism may lead to **myxedema coma**
* AMS
* Hypothermia
* Slowing/Failure of multiple organs
70
The most common cause of hypothyroidism in idodine sufficient countries is _
The most common cause of hypothyroidism in idodine sufficient countries is **Hashimoto's**
71
Hashimoto's thyroiditis is caused by _
Hashimoto's thyroiditis is caused by **auto-antibodies against thyroid peroxidase (TPO) or thyroglobulin**
72
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**
73
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**
74
Hashimoto's thyroditis is associated with _ genetic markers
Hashimoto's thyroditis is associated with **HLA-DR3, HLA-DR5**
75
HLA-B8 is associated with (Graves/Hashimoto's)
HLA-B8 is associated with **Graves**
76
HLA-DR5 is associated with (Graves/Hashimoto's)
HLA-DR5 is associated with **Hashimoto's**
* Both of them are associated with HLA-DR3
77
A hashimoto thyroid may feel _
A hashimoto thyroid may feel **nontender, enlarged, symmetrical, "rubbery"**
78
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
79
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
80
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**
81
Hashimoto's is managed with _
Hashimoto's is managed with **levothyroxine**
82
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
83
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
84
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*
85
How do we manage postpartum thyroiditis?
**Postpartum thyroiditis** is usually self-limiting and no treatment is required
86
Subacute granulomatous thyroiditis is also called _
Subacute granulomatous thyroiditis is also called **De Quervain thyroiditis**
87
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
88
_ 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
89
Clinical signs of De Quervain thyroiditis include _ and _
Clinical signs of De Quervain thyroiditis include **very tender thyroid** and **jaw pain**
90
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
91
De Quervain thyroiditis is associated with _ histology findings
De Quervain thyroiditis is associated with **granulomatous inflammation, multinucleated giant cells, foamy histiocytes**
92
How do we manage subacute granulomatous thyroiditis?
It is usually self-limiting and does not require treatment
* If symptomatic consider corticosteroids
93
Riedel thyroiditis is characterized by _
Riedel thyroiditis is characterized by **the replacement of normal thyroid with fibrous tissue**
* IgG related systemic disease
* Inflammatory infiltrates
94
Clinical signs of Riedel thyroiditis:
Clinical signs of Riedel thyroiditis:
* Fixed, rock-like painless goiter
* Dysphagia
* Hoarseness
* Dyspnea
* Hypothyroidism
95
Riedel will present with _ type goiter
Riedel will present with **rock-like painless goiter**
96
Riedel thyroiditis is associated with an increased risk of developing _
Riedel thyroiditis is associated with an increased risk of developing **thyroid lymphoma**
97
Riedel will present on histology with _
Riedel will present on histology with **fibrous tissue with inflammatory infiltrate**
98
Riedel thyroiditis is managed with _ and _
Riedel thyroiditis is managed with **levothyroxine** and **thyroidectomy**
99
How does iodine deficiency present?
Iodine deficiency presents with **hypothyroidism sx, goiter**
* More common in developing countries
* Manage via iodine
100
Congenital hypothyroidism occurs due to _
Congenital hypothyroidism occurs due to **Ab-mediated maternal hypothyroidism**
* IgG crosses the placenta
101
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
102
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**
103
Congenital hypothyroidism often presents when?
Congenital hypothyroidism often presents **weeks to months after birth**
* Because maternal T4 crosses the placenta
104
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**
105
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
106
_ 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
107
_ is a benign, solitary growth of the thyroid
**Thyroid adenoma** is a benign, solitary growth of the thyroid
108
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
109
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**
110
Thyroid adenomas are associated with (hyperthyroidism/hypothyroidism)
Thyroid adenomas are associated with **hyperthyroidism**
111
How do thyroid adenomas normally present?
**Thyroid adenomas** are associated with hyperthyroidism and thyrotoxicosis; however they are most frequently asymptomatic
112
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
113
The most common form of thyroid cancer is _
The most common form of thyroid cancer is **papillary carcinoma**
114
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**
115
_ test is needed for the diagnosis of papillary carcinoma
**Fine needle aspiration** is needed for the diagnosis of papillary carcinoma
116
The most common presentation of papillary carcinoma is _
The most common presentation of papillary carcinoma is **asymptomatic**
117
Papillary carcinoma has a _ prognosis and is treated via _
Papillary carcinoma has a **very good** prognosis and is treated via **thyroidectomy**
118
Histopathology of papillary carcinoma is likely to show _ and _
Histopathology of papillary carcinoma is likely to show **Orphan Annie nuclei** and **psammoma bodies**
119
Empty appearing nuclei with central clearing describes the histology of _
Empty appearing nuclei with central clearing describes the histology of **papillary carcinoma**
120
Follicular carcinoma is characterized by _
Follicular carcinoma is characterized by **invasion of the thyroid capsule and vasculature**
121
Follicular carcinoma is associated with _ spread
Follicular carcinoma is associated with **hematogenous spread** to the bone and lungs
122
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
123
Follicular carcinoma is associated with mutations in _ and _ translocations
Follicular carcinoma is associated with mutations in **RAS** and **PAX8-PPAR-gamma** translocations
124
Follicular carcinoma is associated with _ prognosis and is treated with _
Follicular carcinoma is associated with **good** prognosis and is treated with **thyroidectomy**
125
Medullary carcinoma is derived from _ cells which release _
Medullary carcinoma is derived from **parafollicular C cells** cells which release **calcitonin**
126
Medullary carcinoma is associated with _ mutations as well as _ phenomenon
Medullary carcinoma is associated with **RET** mutations as well as **MEN2A** and **MEN2B**
127
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**
128
Medullary carcinoma is treated via _
Medullary carcinoma is treated via **thyroidectomy**
129
Anaplastic carcinoma presents with _
Anaplastic carcinoma presents with a **rapidly enlarging neck mass**, often presents in older patients
130
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
131
_ thyroid neoplasm is most likely to present with dysphagia and dyspnea
**Anaplastic carcinoma** is most likely to present with dysphagia and dyspnea
132
Anaplastic carcinoma is associated with _ mutation
Anaplastic carcinoma is associated with **TP53** mutation
133
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
134
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**
135
The thyroid descends (anterior/posterior) to the hyoid bone
The thyroid descends **anterior** to the hyoid bone
136
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
137
The thyroglossal duct obliterates around week _
The thyroglossal duct obliterates around **week 8-10**
138
The dorsal wings *third pharyngeal pouch* becomes the _
The dorsal wings *third pharyngeal pouch* becomes the **inferior parathyroid glands**
139
The dorsal wings *fourth pharyngeal pouch* becomes the _
The dorsal wings *fourth pharyngeal pouch* becomes the **superior parathyroid glands**
140
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**
141
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**
142
The parathyroids develop from the _ and _ pharyngeal pouches
The parathyroids develop from the **third** and **fourth** pharyngeal pouches
143
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
144
Parafollicular (C cells) secrete _
Parafollicular (C cells) secrete **calcitonin**
145
Papillary thyroid carcinoma
146
Follicular carcinoma
147
Anaplastic thyroid carcinoma
148
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**
149
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
150
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**
151
Arrows are pointing to _ cells
**C cells** (parafollicular cells)
152
Normal thyroid follicles are lined with _ and filled with _
Normal thyroid follicles are lined with **follicular epithelium** and filled with **colloid**
153
Multinodular goiter pathology may present on histology with _
Multinodular goiter pathology may present on histology with **hyperplasia, colloid accumulation, nodule formation**
154
Multinodular goiter:
Left shows hyperplasia, top right shows colloid accumulation, bottom right shows nodule formation
155
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
156
The most common cause of hypothyroidisim is _
The most common cause of hypothyroidism is **Hashimoto thyroiditis** aka *chronic lymphocytic thyroiditis*
156
Hurthle cells
156
_ 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
157
Reidel thyroiditis is an autoimmune condition associated with _ antibody
Reidel thyroiditis is an autoimmune condition associated with **IgG4**
158
De Quervain thyroiditis
159
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**
160
_ 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
161
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**
162
Follicular nuclei may have _ or _ in papillary thyroid carcinoma
Follicular nuclei may have **elongation/overlapping** or **dispersed chromatin (clearing)** in papillary thyroid carcinoma
163
Psammoma bodies are also associated with _ thyroid neoplasm
Psammoma bodies are also associated with **papillary thyroid carcinoma**
164
_ 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
165
Anaplastic thyroid carcinoma
166
_ 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
167
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
168
Medullary thyroid carcinoma will have a _ appearnace
Medullary thyroid carcinoma will have a **neuroendocrine appearance** with "packets" of uniform round/oval cells
169
Subclinical hyperthyroidism labs:
Subclinical hyperthyroidism:
Low TSH and TRH. Normal T4 and T3
170
Subclinical hypothyroidism labs:
Subclinical hypothyroidism labs:
High TSH and TRH. Normal T4 and T3
171
Overt primary hyperthyroidism labs:
Overt primary hyperthyroidism labs:
Low TSH and TRH. Hight T4 and T3
172
Overt primary hypothyroidism labs:
Overt primary hypothyroidism labs:
High TSH and TRH. Low T4 and T3
173
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
174
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.
175
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**
176
The best imaging for a thyroid mass is _
The best imaging for a thyroid mass is **ultrasound**
177
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**
178
Identify A
A: Normal
179
Identify B
B: Grave's disease
180
Identify C
C: toxic multinodular goiter
181
Identify D
D: toxic adenoma
182
Identify E
E: thyroiditis
183
Name 5 types of thyroiditis
1. **Lymphocytic thyroiditis** (Hashimoto)
2. **Subacute granulomatous thyroiditis** (De Quervain)
3. **Fibrosing thyroiditis** (Riedel)
4. **Drug induced thyroiditis**
5. **Trauma induced thyroiditis**
184
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
185
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
186
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)
187
We test for an iodine deficiency using _
We test for an iodine deficiency using **urine iodine**
188
_ 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
189
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
190
Estrogens may _ free T3 levels
Estrogens may **decrease** free T3 levels
191
Estrogen decreases free T3 levels by increasing _
Estrogen decreases free T3 levels by increasing **thyroid binding globulin**
192
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**
193
Life threatening hypothyroidism is called _ and results in _ sx
Life threatening hypothyroidism is called **myxedema coma** -->
* Hypothermia
* Hyponatremia
* Bradycardia
* Hypoglycemia
* Hypoxia
* Hypoventilation
* Diffuse swelling
194
Treatment for myxedema coma includes _
Treatment for myxedema coma includes **levothyroxine, liothyronine, glucocoricoids (IV)**
195
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
196
Onycholysis is _
Onycholysis is **separation of the nail from the nail bed**, sign of hyperthyroidism
197
(Methimazole/ PTU) has fewer teratogenic effects but _ has less liver toxicity
**PTU** has fewer teratogenic effects but **methimazole** has less liver toxicity
198
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
199
Papillary carcinoma is associated with gene mutations _ or _
Papillary carcinoma is associated with gene mutations **BRAF** or **RET**
200
Follicular carcinoma is associated with gene mutations _
Follicular carcinoma is associated with gene mutations **RAS**
201
Medullary carcinoma is associated with gene mutations _
Medullary carcinoma is associated with gene mutations **RET** (and MEN2A and 2B)
202
Anaplastic carcinoma is associated with gene mutations _ or _
Anaplastic carcinoma is associated with gene mutations **p53** or **RAS**
203
Hyperactive thyroid nodule
204
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**
205
Medullary carcinoma should be monitored via _ levels
Medullary carcinoma should be monitored via **calcitonin levels**
