Lec 01: Pathology of Thyroid and Parathyroid Flashcards

1
Q

True of the thyroid gland EXCEPT

A. weighs 15-25 g in the adult
B. found between the cricoid cartilage and suprasternal notch
C. normally moves with deglutition and palpable
D. made up of follicles surrounding colloid
E. NOTA

A

C.

The thyroid gland is normally not palpable.

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2
Q

Enumerate three arteries that supply the thyroid gland.

A

superior thyroid artery
inferior thyroid artery
thyroid ima artery

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3
Q

The thyroid ima artery branches from what main vessel?

A. external carotid artery
B. thyrocervical trunk
C. brachiocephalic trunk
D. inferior laryngeal artery
E. NOTA
A

C.

The following arises from

STA - external carotid artery
ITA - thyrocervical trunk
TIA - brachiocephalic trunk

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4
Q

ID: Extra thyroid tissue located near the isthmus found in some people.

A

pyramidal lobe

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5
Q

ID: Other name for follicular epithelial cells.

A

thyrocytes

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6
Q

T/F: The morphology of the thyrocytes can differentiate between metabolically active and inactive cells.

A

T

Metabolically active thyrocytes are taller and more columnar.

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7
Q

T/F: Parafollicular cells are not visible in typical staining.

A

T

C cells are pale-staining in routine H&E preparation. Immunohistochemical staining using antibody against calcitonin should be used to visualize C cells.

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8
Q

Differentiate thyrotoxicosis from hyperthyroidism.

A

thyrotoxicosis - state of increased thyroid hormones (T3 and T4) from any etiology

hyperthyroidism - state of thyroid gland hyperfunction leading to thyrotoxicosis

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9
Q

Causes of hyperthyroidism EXCEPT

A. nodular toxic goiter
B. exogenous hormone intake
C. TSH-secreting pituitary adenoma
D. Graves' disease
E. NOTA
A

B.

Technically, exogenous hormone intake is not a form of hyperthyroidism since the thyroid gland is not hyperfunctioning.

However, it is still classified as hyperthyroidism in the transcription, since thyrotoxicosis and hyperthyroidism are used synonymously.

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10
Q

T/F: Thyrotoxicosis due to thyroiditis is a form of hyperthyroidism.

A

F

Technically, again, in thyroiditis, there is only a spillage of preformed thyroid hormone due to thyrocyte desctruction and not due to thyroid gland hyperfunction.

However, again, it was also classified as hyperthyroidism due to synonymous usage with thyrotoxicosis.

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11
Q

T/F: Thyroid carcinomas are rarely functioning.

A

T

Most carcinoma are non-functional and appear as cold nodules.

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12
Q

Signs of thyrotoxicosis EXCEPT

A. tachycardia
B. fine resting tremors
C. lid lag
D. dry skin
E. NOTA
A

D.

Thyrotoxicosis presents with warm, sweaty, and flushed skin due to vasodilation and increased sweating due to sympathetic stimulation.

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13
Q

These group of symptoms are the earliest and most consistent to appear in a thyrotoxic state.

A. cardiac
B. sympathetic
C. ocular
D. dermatologic
E. gastrointestinal
A

A.

Cardiac signs include

  • tachycardia
  • palpitations
  • arrhythmia
  • high-output heart failure
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14
Q

ID: Pathophysiology of the wide, staring gaze, and lid lag in thyrotoxicosis.

A

overstimulation of the superior tarsal muscle (Muller’s muscle) which retracts the upper eyelid

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15
Q

T/F: True thyroid ophthalmopathy associated with proptosis occurs only in Graves’ disease.

A

T

Proptosis in GD is caused by accumulation of water-retaining glycosaminoglycans in the retro-orbital space leading to proptosis and exophthalmos.

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16
Q

The following are signs and symptoms of thyrotoxicosis EXCEPT

A. heat intolerance
B. weight loss
C. insomnia
D. constipation
E. NOTA
A

D.

SNS overactivity results in GI hypermotility leading to diarrhea, not constipation.

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17
Q

ID: This type of thyrotoxicosis commonly occurs in older adults, in whom advanced age and various co-morbidities may blunt / mask the features of thyroid hormone excess.

A

apathetic thyrotoxicosis

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18
Q

ID: The most useful single screening test for hypothyroidism.

A

TSH

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19
Q

The most consistent laboratory finding in thyrotoxicosis.

A. increased T4 / T3
B. decreased TSH
C. increased RAIU
D. increased TRH
E. AOTA
A

A.

Increased TSH can be found in TSH-secreting pituitary adenoma.

Decreased RAIU can be found in most types of thyroiditis.

Decreased TRH is the expected response in thyrotoxicosis.

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20
Q

True of radioactive iodine uptake EXCEPT

A. surrogate marker of thyroid hormone synthesis
B. 10-25% of iodine is taken by the gland in normal states
C. up to 40% can be taken in hyperthyroidism
D. reflects the metabolic activity of the gland
E. NOTA

A

E. NOTA

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21
Q

The following are primary causes of hypothyroidism EXCEPT

A. Hashimoto thyroiditis
B. thyroid agenesis
C. radiation-induced ablation
D. postpartum pituitary necrosis
E. NOTA
A

D.

Postpartum pituitary necrosis (Sheehan syndrome) is a type of secondary hypothyroidism. It is due to deficient secretion of TSH due to hypopituitarism.

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22
Q

Enumerate three causes of tertiary hypothyroidism.

A

Tertiary hypothyroidism refers to deficient TRH secretion. It may be due to

  • brain tumors
  • brain trauma
  • radiation to the brain
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23
Q

Signs and symptoms of cretinism EXCEPT

A. protuberant tongue
B. coarse facial features
C. tall stature
D. mental retardation
E. NOTA
A

C.

short stature

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24
Q

True of myxedema EXCEPT

A. accumulation of mucopolysaccharide ground substance in dermis
B. acquired in early childhood
C. slowing of physical and mental activity
D. cold intolerance
E. NOTA

A

B.

Myxedema is acquired during LATE childhood or adulthood.

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25
Q

Possible laboratory findings in hypothyroidism EXCEPT

A. increased T4 / T3
B. increased TSH
C. decreased TSH
D. decreased RAUI
E. NOTA
A

E. NOTA

increased TSH - primary hypothyroidism
decreased TSH - secondary hypothyroidism

26
Q

T/F: Thyroid diseases are more common in females.

A

T

27
Q

Which of the following thyroiditides (plural of thyroiditis) is/are painful?

A. infectious thyroiditis
B. subacute lymphocytic thyroiditis
C. subacute granulomatous thyroiditis
D. Hashimoto thyroiditis
E. AOTA
A

A & C

IT and SGT (de Quervain thyroiditis) are both painful.
SLT and HT are both painless.

28
Q

Pathologic picture of infectious thyroiditis

A. Langhans type giant cells
B. lymphocytic infiltration
C. neutrophilic infiltration
D. Hurthle cells
E. AOTA
A

C.

IT exhibits neutrophilic infiltration characteristic of a suppurative response. Treatment is aggressive antibiotic therapy.

29
Q

ID: What two thyroiditides exhibits lymphocytic infiltration?

A

subacute lymphocytic thyroiditis
Hashimoto thyroiditis

Note that both of them are also painless.

30
Q

ID: What is the pathologic difference between subacute lymphocytic thyroiditis and Hashimoto thyroiditis?

A

There are no germinal centers nor Hurthle cells in SLT.

31
Q

True of SGT / de Quervain thyroiditis

A. viral / post-viral inflammatory response
B. damage mediated by cytotoxic T cells
C. presents with fever
D. A & B only
E. AOTA
A

E. AOTA

32
Q

ID: Pathologic picture of SGT / DQT

A

chronic inflammatory infiltrates with multinucleate giant cells

33
Q

Enumerate two differentials for SGT / DQT.

A

infectious thyroiditis

tuberculosis

34
Q

ID: This thyroiditis is commonly mistaken as a carcinoma due to its dense and hard morphology.

A

Riedel fibrosing thyroiditis / ligneous thyroiditis

35
Q

Which serotype is associateed with Hashimoto thyroiditis?

A. HLA-DR5
B. HLA-B8
C. HLA-DR3
D. A & B only
E. AOTA
A

A.

B8 and DR3 are associated with Graves’ disease.

36
Q

T/F: Humoral immunity inflicts more damage to the thyroid in Hashimoto thyroiditis.

A

F

Cellular immunity (CD8+ T cells) inflicts more damage.

37
Q

True of Hurthle cells EXCEPT

A. suggestive of degenerative phenomenon
B. agranular cytoplasm due to decreased mitochondria
C. thyrocytes with abundant pink, eosinophilic cytoplasm
D. aka oncocytes or Ashkenazy cells
E. NOTA

A

B.

Hurthle cells appear GRANULAR due to INCREASED mitochondrial content.

38
Q

Enumerate the clinical triad of Graves disease.

A

hyperthyroidism
ophthalmopathy
dermopathy

39
Q

ID: Typical laboratory finding in Graves disease

A

^ T3
^ T4
^ RAIU
v TSH

40
Q

ID: Long-acting thyroid stimulator which leads to increased release of T3 and T4

A

thyroid stimulating immunoglobulin (TSI)

41
Q

ID: Thyroid autoantibody which promotes proliferation and enlargement of thyrocytes

A

thyroid growth immunoglobulin (TGI)

42
Q

T/F: Graves’ disease can present with hypothyroidism.

A

T

TSH binding-inhibiting immunoglobulins (TBII) may either bind to receptors enhancing thyroid hormone synthesis or may block binding of TSH to the receptor decreasing hormone synthesis.

Therefore TBII may cause episodes of hyper and hypothyroidism.

43
Q

ID: Gross pathologic picture of Graves’ disease

A

diffuse toxic goiter

44
Q

T/F: The papillae / papillary projection inside the follicular lumen in Graves’ disease contains a fibrovascular core.

A

F

The fibrovascular core is ABSENT, in contrast with a papillary thyroid carcinoma where the fibrovascular core is present.

45
Q

Explain the scalloping apppearance of the colloid in Graves’ disease.

A

It is due to the active thyroid hormone synthesis and hence active uptake of colloid.

46
Q

True of the microscopic pathologic morphology of Graves’ disease EXCEPT

A. diffuse hypertrophy and hyperplasia of thyrocytes
B. lymphoid infiltrates without germinal centers
C. involutional changes after therapy
D. pseudopapillae
E. NOTA

A

B.

Germinal centers are common in Graves’ disease. This is why Hashimoto thyroiditis may be a differential based on morphology.

47
Q

ID: Most common cause of goiter

A

iodine deficiency

This leads to impaired thyroid hormone synthesis leading to increased secretion of TSH and subsequent hypertrophy and hyperplasia of thyrocytes.

48
Q

Sporadic causes of goiter EXCEPT

A. idiopathic
B. hereditary enzyme defects
C. intake of goitrogens
D. iodine deficiency
E. NOTA
A

D.

Iodine deficiency goiter is ENDEMIC goiter.

49
Q

Risk factors predisposing thyroid nodules to progression into malignancy EXCEPT

A. solitary
B. male gender
C. history of irradiation
D. hot nodule
E. NOTA
A

D.

Hot nodules are often benign.
10% of cold nodules are malignant.

50
Q

ID: This is the most common type of malignant thyroid neoplasm.

A

papillary thyroid carcinoma

51
Q

ID: These are empty or ground glass nuclei that are pathognomonic for papillary thyroid CA.

A

Orphan Annie eye nuclei

52
Q

Which of the following has a tendency for hematogenous dissemination?

A. papillary thyroid CA
B. follicular thyroid CA
C. anaplastic thyroid CA
D. medullary thyroid CA
E. AOTA
A

B.

53
Q

This thyroid CA has the worst prognosis

A. papillary thyroid CA
B. follicular thyroid CA
C. anaplastic thyroid CA
D. medullary thyroid CA
E. AOTA
A

C.

Mortality rate approaches 100%.

54
Q

Spindle cells and giant cells are characteristic of this thyroid CA.

A. papillary thyroid CA
B. follicular thyroid CA
C. anaplastic thyroid CA
D. medullary thyroid CA
E. AOTA
A

C.

55
Q

This is a neuroendocrine tumor of the parafollicular cells.

A. papillary thyroid CA
B. follicular thyroid CA
C. anaplastic thyroid CA
D. medullary thyroid CA
E. AOTA
A

D.

56
Q

What is the only way to sufficiently differentiate a follicular thyroid adenoma from a follicular thyroid carcinoma?

A

generous and exhaustive sampling of the CAPSULE

The morphologic features of FTA and FTC are very much the same such that the only way to differentiate them is through capsular and vascular invasion.

57
Q

ID: These are concentrically calcified structures often found in the core of protruding papillae.

A

psammoma bodies

58
Q

T/F: Psamomma bodies are highly specific of papillary thyroid CA.

A

T

They are almost never found in follicular and medullary CA.

59
Q

ID: These cells are found in adenoma, carcinoma, and hyperplasia of the parathyroid gland.

A

Wasserhell cells / “water clear” cells

60
Q

T/F: Parathyroid hyperplasia typically involves one gland.

A

F

It usually involves all four glands.