Thyroid and Neck unit Flashcards
1
Q
What does the term ‘Adam’s Apple’ refer to?
A
Laryngeal prominence
2
Q
List the 4 strap muscles and where are they?
A
sternohyoid, sternothyroid, thyrohyoid, and omohyoid. located anterior to the thyroid
3
Q
Where is the longus coli muscle?
A
posterior to the thyroid (forming the posterior border)
4
Q
Where is the sternocleidomastoid muscle?
A
lateral and more superficial to the strap muscles
5
Q
Where are the scalene muscles?
A
posterior and lateral in the neck
6
Q
How can you differentiate a possible mass from a muscle in the neck?
A
look in sag and transverse, if you cant see it in both planes, its a muscle
7
Q
What side of the thyroid is the esophagus seen on?
A
left side of the neck
8
Q
Where is the basic location of the parathyroid glands?
A
typically 4 parathyroids, 2 superior and posterior to the mid/upper thyroid, and 2 inferior and posterior to the lower thyroid
9
Q
Neck segments: describe 1A, 1B and what is seen in 1B?
A
1A: submental
1B: submandibular area, contains the SMG
10
Q
Neck regions: What is seen in 2A? Where is 2B?
A
2A contains the jugulodigastric node and IVJ
2B is posterior to the IVJ
11
Q
Neck regions: What does level 3 contain a part of? What does level 4 contain?
A
Level 3 contains a portion of the SCM
Level 4 contains the medial supraclavicular nodes
12
Q
Describe the difference in location for 5A and 5B, and what does 5B contain?
A
5A is the superior portion, 5B is the inferior portion
5B contains the lateral supraclavicular nodes
13
Q
Neck regions: Where is level 6 and where is level 7?
A
Level 6 is superior to level 6/suprasternal notch
Level 7 is in the suprasternal notch of the neck
14
Q
What is the thyroid gland and what does it do?
What does the thyroid control?
A
it is an endocrine gland and it synthesizes, stores and secretes hormones (directly into bloodstream)
- controls the BMR: basal metabolic rate (rate at which the body uses energy at rest to keep organs going)
15
Q
What are the 3 hormones secreted by the thyroid gland?
A
T3: triiodothyronine
T4: thyroxine
Calcitonin
16
Q
Which cells secrete calcitonin and what role does it play?
A
secreted by the parafollicular cells
lowers blood calcium level (inhibits calcium release from the bone)
17
Q
What cells secrete T3 and T4?
A
follicular cells
18
Q
What does the regulatory system involve?
A
hypothalamus, pituitary gland and the thyroid gland
- maintains T3 and T4 levels
19
Q
What is thyrotropin also known as? What is it regulated by?
A
same as thyroid stimulating hormone (TSH) and is released from the pituitary gland
- regulated by T3, T4 and thyrotropin releasing hormone (TRH)
20
Q
Describe the negative feedback loop of the thyroid gland
A
1- decrease in thyroid hormone decreases the BMR 2- decrease in the BMR stimulates TRH 3- TRH induces the release of TSH 4- thyroid releases T3 and T4 5- BMR returns to normal
21
Q
What is the average size of the thyroid gland? What is it covered by?
A
4-6cm in length, 1.3-1.8cm AP
covered in a fibrous capsule
22
Q
How much does the thyroid gland weigh?
A
15-20g in adults
23
Q
Explain the blood flow of the thyroid
A
2 superior thyroid arteries arising off the ECA
2 inferior thyroid arteries arising from thyrocervical trunk of the subclavian artery
possible thyroid IMA artery (variation that typically supplies the isthmus)
24
Q
Explain the venous drainage of the thyroid gland
A
2 superior thyroid veins, 2 middle thyroid veins, 2 inferior thyroid veins
superior and middle drain into IJV
inferior drains into BCV
25
What is the most severe thyroid variation?
athyrosis
- associated with cretinism
- congenital absence of the gland
26
Thyroid variations: What is a thyroglossal tract?
traces of epithelial cells that normally solidifies and *should* ultimately atrophy
-where the thyroid descends during development
27
What is the most common thyroid variation?
pyramidal lobe: typically extends upwards from the isthmus, or from either lobe
28
Where is the most common location for an ectopic thyroid gland?
can be at any level along the duct but most commonly lingual (sublingual?)
29
What does the parathyroid glands produce?
| What do they look like
produce parathyroid hormone
| oval/almond shaped measuring up to 5mm
30
What is the primary source of production of the parathyroid hormone? (PTH)
What does PTH regulate?
chief cells
- blood calcium levels and phosphorus levels
31
What organs is PTH important for?
bones, kidneys and intestins
32
Describe the parathyroid feedback loop
increase in calcium levels prevents further PTH secretion
| - when blood calcium levels become low, PTH secretion increases
33
What tests are done when looking at parathyroid levels?
lab tests that are usually fasting to test the PTH and calcium levels in the blood
34
List some anatomic variations of the parathyroid glands
accessory glands, absence of one or more
can be ectopic (in 15-20%): most commonly in anterior mediastinum
can be intrathyroidal, and tends to remain symmetrical even when ectopic
35
What is the purpose of the thymus gland?
plays a role in immune function, releases thymosin (necessary for T cell production)
largest in children and is replaced by fat after puberty
36
What provides the diagnosis between benign or malignant thyroid pathology?
FNA cytology
37
What is another term for hyperthyroidism and what is it?
thyrotoxicosis
| - hypermetabolic state caused by elevated levels of free T3 and T4
38
What is primary hyperthyroidism?
excess thyroid hormone that is synthesized and secreted by the thyroid gland
- TSH is increased
39
What is secondary hyperthyroidism?
less common and caused from an outside source such as an TSH secreting pituitary adenoma
- TSH is decreased
40
What is the most common cause of thyrotoxicosis?
hyperthyroidism (type of thyrotoxicosis)
| -you can have thyrotoxicosis without hyperthyroidism
41
What is the most common cause of hyperthyroidism and describe what it is
Graves disease, is an autoimmune disease that can occur at any age (*40-60s) with female predominance
42
What is the etiology of graves?
can be hereditary, from the immune system, age, gender or stress related
43
What is the classic triad of graves disease?
diffuse thyroid enlargement (goiter)
ophthalmology (protrusion of the eyes)
graves dermopathy (pretibial myxedema)
44
What are the clinical manifestations of hyperthyroidism and graves disease?
tachycardia at rest, excessive sweating, *heat intolerance*, weight loss
45
What is the sonographic appearance of hyperthyroidism/graves?
normal or enlarged in size
heterogenous when enlarged
hypervascularity is common (*thyroid inferno*)
46
What is the most common thyroid function disorder and describe what it is
hypothyroidism, is a decrease in thyroid hormone production
47
What is the most common type of hypothyroidism?
primary: intrinsic abnormality
48
Describe what secondary hypothyroidism is
the pituitary or hypothalamus is being affected in a way that results in failure to stimulate normal thyroid function
- related to damage or disease to those glands (adenomas, tumours, meds etc)
49
What is the most common cause of primary hypothyroidism world wide?
- in iodine deficient areas?
iodine deficiency
| chronic autoimmune thyroiditis/ Hashimoto's (75%)
50
What is primary hypothyroidism associated with?
other autoimmune diseases (Sjogren's, lupus, Rh arthritis)
| - also genetic predisposition, high iodine intake (Wolff-chaikoff), selenium deficiency, smoking and chronic hep C
51
Describe what the Wolff-Chaikoff effect is
an auto-regulatory phenomenon
- excess iodine interrupts the normal production of thyroid hormones and is usually temporary, but in patients with underlying thyroid disease the suppressive action can persist and result in iodine-induced hypothyroidism
52
What are the key clinical manifestations of hypothyroidism?
weakness/fatigue, dry skin, *cold intolerance*, hoarseness, weight gain, constipation, menstrual irregularities, and decreased sweating
53
What is the sonographic appearance of Hashimoto's?
can look similar to graves, diffusely heterogenous
*moderately enlarged, lobular without calcs or necrosis*
often hypervascular
if in late stages it can appear ill defined and atrophic
54
What is the most common presentation of thyroiditis? (what condition can it come
from)
hypothyroidism or thyrotoxicosis followed by hypothyroidism
55
What is the possible cause for subacute thyroiditis?
| What else can subacute thyroiditis be referred to as?
possibly from a viral cause
also De Quervain Disease or granulomatous thyroiditis
56
What are the clinical presentations of subacute thyroiditis?
when does it resolve and when is recovery
neck pain that can radiate to upper jaw, throat and ears
unilateral or bilateral enlargement of the gland
usually a temporary condition that resolves in 2-6weeks with spontaneous recovery of function in 6-8weeks
57
What are the sonographic appearances of subacute thyroiditis?
enlargement, hypoechoic, normal/decreased vascularity, and nodularity
58
What are 15-25% of solitary thyroid nodules? (sono appearance)
What is the treatment for benign vs malignant?
either cystic or mostly cystic (due to degeneration or hemorrhage)
benign: percutaneous ethanol injection
malignant: surgically removed
59
What are the types of complex thyroid cysts? (not spongiform)
colloid cysts and hemorrhagic cysts
| both have low malignant suspicion
60
What is the cause of colloid cysts?
they are irregularly enlarged follicles containing abundant colloid
they may have multiple echogenic foci with comet tail artifacts or calcifications
61
Explain what a hemorrhagic cyst is
may contain blood and debris
it may have complex internal echoes, septa, and debris (layered debris at dependent portion is highly characteristic of hemorrhage)
62
What increases the frequency of getting thyroid nodules, what decreases the frequency?
frequency increases with age, it decreases with iodine intake
63
What is a hot nodule?
hyperfunctioning/autonomous: area of dense collection of activity on nuclear med imaging
approx 5-10%
64
What is a cold nodule?
non functioning nodule: area of decreased or absent activity on nuc med images
approx 80-85% of patients are cold, 10-15% of these nodules are malignant
65
What is a thyroid adenoma?
| What can it produce and cause?
it is a benign neoplasm that is slow growing with a fibrous capsule and usually solitary
incidence increased with age 50-60%
they are rare and can produce thyroid hormones and can cause hyperthyroidism
66
What are most thyroid adenomas derived from?
follicular cells
67
What is the sonographic appearance of a thyroid adenoma?
variable appearances
most common appearance is solitary, well circumscribed and oval/circular
rim calcifications, complete/incomplete halo
spoke wheel colour doppler appearance
68
What is goiter?
| What is a reliable marker?
enlargement of the thyroid gland, can be variable in side
can be toxic or non toxic, simple or multinodular and more common in women
reliable marker is an isthmus >1cm
69
What is the symptoms of goiters?
dysphagia, inspiratory stridor (high pitch turbulent sound when you breath from compression of the vocal cords)
venous congestion and hoarseness
70
Explain what non-toxic goiter is
Endemic goiter?
Sporadic goiter?
typically euthyroid (normal thyroid function), can be simple or multinodular
endemic: due to iodine deficiency in food, water and soil in an area
sporadic: occurs spontaneously in euthyroid patients in iodine sufficient areas, peak incidence 35-60yo
71
What are probable causes of sporadic non toxic goiter?
thought to be due to ingestion of certain drugs/meds that or hereditary factors
72
What can toxic goiter induce?
thyrotoxicosis
| is typically multinodular
73
Explain multinodular goiters
multi-lobulated, asymmetrical enlargement, be unilateral or bilateral, can extend below the clavicle/sternum (plunging)
can be nontoxic or toxic
74
What is the sonographic appearance of multinodular goiters?
heterogenous, lobulated and multinodular
75
What is the most common thyroid carcinoma? Second most common?
What % of thyroid nodules are malignant?
1st: papillary
2nd: follicular
5-6.5%
76
What increases the incidence of thyroid carcinoma?
radiation exposure
77
What are the sonographic appearances of thyroid carcinomas?
typically solid and hypoechoic, microcalcs are one of the most specific features of malignancy**
taller than wide shape, ill defined margins, central hypervascularity
*lymph node mets are highly suspicious thyroid malignancy
78
What is the most common type of thyroid cancer? Explain how aggressive this is and the peak incidence
papillary carcinoma (75-85%)
is the least aggressive thyroid ca with great prognosis
peak incidence 20-50
79
What is the clinical presentation of papillary carcinoma?
painless palpable lump
palpable nodule with enlarged cervical lymph nodes
enlarged cervical nodes without a palpable nodule
80
What is the sonographic appearance of papillary carcinoma?
| What can be seen if there is mets to the lymph nodes?
hypoechogenicity (90%)
microcalcs, hypervascular with disorganized vessels
punctate microcalcs may appear in the affected lymph nodes if mets are present
81
What is the second most common thyroid cancer? Explain the incidence rates
```
follicular carcinoma (10-20%)
peak incidence 40-50yo, increased in areas of dietary iodine deficiency
```
82
What are the clinical presentations of follicular carcinoma?
slow growing painless nodule
| mets occur in the bone, liver or lungs (NOT in the neck lymph nodes)
83
What is the sonographic appearance of follicular carcinoma?
Is FNA helpful or not?
What are the features of malignancy, although rare?
appearance looks like follicular adenomas
- FNA cant tell the difference between the two, needs cytology smear
irregular margins, thick irregular halo, hypervascularity
84
Describe medullary carcinoma
| what does it not respond to
makes 5% of thyroid cancers, from parafollicular cells (c-cells), is a more aggressive type that does not respond to chemo or radiation, and is more common in females (slightly)
85
What is the clinical presentation of medullary carcinoma?
mass in the neck that can cause dysphagia or hoarseness
patients often suffer a number of symptoms that are related to endocrine secretions ( carcinoid syndrome: serotonin, and Cushings)
86
What is the sonographic appearance of medullary carcinoma?
similar to papillary with local invasion and mets to cervical nodes (more common in patients with medullary ca)
87
Describe anaplastic thyroid carcinoma
| Survival rate?
makes 5% of thyroid ca, is aggressive with poor prognosis and widespread mets, there is no effective treatment
less than 10% of patients survive more than 5 years due to the wide spread mets
88
What is the clinical presentation of anaplastic thyroid ca?
rapidly enlarging neck mass with symptoms relating to the destruction of local structures
89
What is the sonographic appearance of anaplastic thyroid ca?
large, solid, hypoechoic mass with demonstration of encasing/invading blood vessels and possible invasion of other nearby structures
90
What is Hurthle Cell ca? How is it classified?
3% of thyroid ca, is an aggressive form with poor prognosis, MORE IN MALES
-either benign Hurthle cell adenoma OR malignant Hurtle cell carcinoma (based on histology)
91
What is the clinical presentation and sonographic appearance of Hurthle cell ca?
variable depending on size/extent, and widely variable
92
What is the clinical presentation of thyroid lymphoma? How is it treated?
rapidly growing mass and symptoms of airway obstruction with a hx of long standing thyroiditis/hashimotos
radiation and chemo
93
What is the sonographic appearance of thyroid lymphoma?
large, solid, hypoechoic mass
infiltration of thyroid parenchyma and even encasement of neck vessels, lobulations and cystic areas (possibly)
non specific Doppler, can be hypovascular or have chaotic blood vessel distribution
94
What forms thyroid lymphoma?
thyroid lymphocytes that turn into cancer cells
95
Describe thyroid mets
| Where are they most commonly from?
very uncommon, occurs in late disease progression of another cancer
more commonly spread by blood rather than lymphatic routes
- melanoma, breast, lung, RCC
96
What causes thyroid disease in pregnancy?
hormonal and physiological changes
| - a common sign is an increase in thyroid size in about 15% of women
97
What is the most common type of thyroid disease in/from pregnancy?
postpartum thyroiditis in post delivery women
| - can occur after abortion or miscarriage, risk is increased with type 1 diabetes or patients with previous hx of PPT
98
When do you not treat a thyroid nodule as spongiform?
if cystic components are less than 50%, or if other features such as peripheral calcs or microcalcs are present
99
When can a nodule be considered almost completely solid?
when the cystic components are less than 5% of the nodule
100
What is a very hypoechoic nodule considered in relation to?
the surrounding muscles
101
What is considered large comet tail artifact?
larger than 1mm and V shaped (is not concerning)
102
What defines a macrocalc?
greater than or equal to 2mm
103
What are the complications of FNA?
risk of bleeding or infection, voice hoarseness or seeding of cancer (although rare)
104
When is FNA effective? (for what nodules)
papillary, medullary and anaplastic
| NOT follicular, Hurthle cell ca or lymphoma
105
What are the major paired salivary glands? What is their purpose?
Submandibular, parotid and sublingual
| they secrete enzymes for chewing and digestion
106
Which is the largest salivary gland and explain its composition
parotid, located in the parotid space
| has superficial and deep lobes separated by the facial nerve, with a fibrous capsule
107
In what salivary gland are tumours and neoplasms most common?
paroritd
108
What is the sonographic appearance of the parotid gland?
homogenous, increased echogenicity compared to muscles, and intraparotid nodes are common
fatty infiltration can occur with age
109
What is a Warthins Tumour?
| What is it associated with?
benign tumour most commonly in the tail of the parotid gland, bilateral in 10-15% of cases
associated with smoking and irradiation
110
What is the sonographic appearance of a Warthins Tumour?
well defined ovoid lesion with multiple irregular cystic areas, larger ones have more cystic components
hypervascular
111
What is a pleomorphic tumour?
| Where is it most commonly located?
also a benign mixed tumour, is the most common salivary gland tumour
most commonly in the parotid and associated with prior neck irradiation
112
What is the sonographic appearance of a pleomorphic tumour?
hypoechoic mass with possible posterior enhancement
113
How is a pleomorphic tumor treated?
surgery (either partial or total) due to risk of malignant transformation
114
What is the Duct of Rivinus? What is the major sublingual duct?
collection of smaller excretory ducts that drain the sublingual glands
Bartholin duct
115
What secretes saliva into the Whartons Duct?
submandibular gland, produces the majority of the saliva in the mouth with a fibrous capsule
116
What is the most common salivary gland disease?
sialolithiasis: stones in the ducts or parenchyma of the salivary glands
most common in the SMG, more common in males aged 30-60
117
What is the clinical presentation of sialolithiasis?
recurrent pain and swelling in area of affected gland, can cause infections, chronic obstructions can case the gland to undergo fatty atrophy
118
What is sialadenitis?
```
inflammation of the salivary glands due to either:
acute bacterial sialadenitis
acute viral sialadenitis
chronic sialadenitis
acute sialadenitis
or sialolithiasis (common cause)
```
119
What is the sonographic features of acute sialadenitis?
| chronic?
enlarged, hypoechoic, hyperemic, possible duct dilatation
atrophic, diffusely hypoechoic with irregular margins (like a cirrhotic liver)
120
What is Sjogren Syndrome?
autoimmune condition of the exocrine glands that produce tears or saliva, more common in females
121
What is the clinical presentation of Sjogren?
dry eyes and inflammation, dry mouth, bilateral parotid enlargement
122
What is the sonographic appearance of early stage Sjogren? late stage?
normal or enlarged and hypoechoic
atrophic gland with multicystic appearance
123
What is Mikulicz syndrome?
used to be called Sjogren's type 1, considered to be on the IgG4 disease spectrum
is non specific inflammatory enlargement of at least 2 or more of the salivary and lacrimal glands
124
What is the clinical presentation of Mikulicz?
bilateral painless symmetrical swelling of the lacrimal and salivary glands, xerostomia (dry mouth) and xeropthalmia (dry eyes)
125
What are the sonographic features of Mikulicz?
enlargement of the glands, diffuse and symmetrical with non specific lymph node involvement
126
What is a thyroglossal duct cyst?
congenital defect in the thyroglossal duct if it persists beyond development, most are found before age 10
typically more than 3cm in size, and increases the risk of infections
127
What is a branchial cleft cyst?
congenital defect, branchial cleft is a thin tract extending from the pharyngeal cavity to an opening near the auricle or neck
abnormalities along this can lead to cysts, sinuses or fistulae (typically singular and unilateral)
128
What is the 1st branchial cleft?
2nd?
3rd?
4th?
- cysts either in the auditory canal (type 1) or submandibular area (type 2)
- most common, located along upper/anterior part of SCM muscle or adjacent to it
- rare and located deep to SCM
- rare with variable location
129
What is a branchial cleft fistula?
when the cleft fails to involute
130
What is a cystic hygroma?
congenital defect as a result of damage or an error in development of the cervical lymphatic system
has a strong association with chromosomal abnormalities
131
What is the sonographic appearance of a cystic hygroma?
multiloculated, septated cystic mass at the posterior lateral aspect of the neck
132
List some other neck pathologies
deep neck space infections, hematomas, and cervical lymphadenopathy
133
Explain a deep neck space infection
| where is the most common space for an abscess?
abscess vs infection/phlegmon, commonly caused by dental infections in adults and tonsilitis in children
submandibular space, retropharyngeal space and parapharyngeal space
134
What is the clinical presentation of a deep neck space infection?
recent dental procedures or recent other infections, neck or mouth trauma
pain, difficulty swallowing
can be idiopathic
135
What is the gold standard imaging for a deep neck space infection?
What are the sonographic findings?
CT, US is used to describe the appearance in relation to anatomy
abscess: fluid filled (partial or complete), thick walls, can have gas collection
enlarged and reactive lymph nodes in the adjacent areas
136
What are common causes of lymphadenopathy?
infections, autoimmune disease and neoplastic causes
generalized is usually from a viral infection
137
What is the sonographic appearance of lymphadenopathy?
| What about mets from PTC?
round, hypoechoic, absence of the fatty hilum, cystic necrosis within
increasing size on serial exams
mixed vascularity
calcifications in the nodes is common and the node appears hyperechoic
