Endocrine - Pathology (Part 1) Flashcards Preview

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Flashcards in Endocrine - Pathology (Part 1) Deck (80)
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1
Q

A 30-year-old male comes to you with the presentation shown. What is the likely diagnosis?

A

Cushing's disease, which constitutes 70% of cases of Cushing's syndrome

2
Q

A biopsy of a thyroid cancer is shown here. What type of thyroid cancer is this?

A

Papillary carcinoma

3
Q

Fundoscopic exam of a patient with longstanding diabetes mellitus reveals the image shown. What is the diagnosis?

A

Diabetic retinopathy; characterized by hemorrhages, exudates, microaneurysms, and vessel proliferation

4
Q

A patient with Cushings syndrome has an increased adrenocorticotropic hormone level; what are two mechanisms of increased adrenocorticotropic hormone production?

A

Overproduction of adrenocorticotropic hormone by the pituitary and overproduction of adrenocorticotropic hormone by an ectopic site (such as in small-cell lung cancer)

5
Q

A patient with Cushings syndrome has a decreased adrenocorticotropic hormone level; what are two mechanisms of increased cortisol production with low adrenocorticotropic hormone levels?

A

Overproduction of cortisol by the adrenal cortex or administration of exogenous cortisol

6
Q

A patient is diagnosed with small-cell carcinoma of the lung leading to Cushings syndrome. Will this patients adrenocorticotropic hormone level be high or low?

A

High

7
Q

A patient is diagnosed with primary adrenal cortical hyperplasia. Will this patients adrenocorticotropic hormone level be high or low?

A

Low

8
Q

What is the effect of long-term steroid administration on adrenocorticotropic hormone?

A

Suppression of the hypothalamic-pituitary-adrenal axis causing low adrenocorticotropic hormone levels

9
Q

What is Cushings disease?

A

An adrenocorticotropic hormone-hypersecreting primary pituitary adenoma

10
Q

What are the results of a low dose dexamethasone suppression test in a healthy person?

A

Decreased cortisol level; dexamethasone decreases adrenocorticotropic hormone secretion by negative feedback leading to decreased cortisol levels

11
Q

What results would you expect after a dexamethasone suppression test in the setting of an adrenocorticotropic hormone-producing pituitary tumor?

A

With low-dose dexamethasone, we would expect high cortisol levels (no suppression); with high doses of dexamethasone, we would expect suppression and thus low adrenocorticotropic hormone and cortisol levels

12
Q

Would cortisol levels be high or low after a high-dose dexamethasone suppression test in a patient with an ectopic adrenocorticotropic hormone-producing tumor?

A

High; the secretory activity of this tumor is independent of negative feedback

13
Q

Would cortisol levels be high or low after a high-dose dexamethasone suppression test in a patient with a cortisol-producing tumor?

A

High; the secretory activity of this tumor is independent of negative feedback

14
Q

What findings are indicative of Cushings syndrome?

A

Hypertension, weight gain, moon facies, truncal obesity, buffalo hump, hyperglycemia (insulin resistance), skin changes, osteoporosis, amenorrhea, and immune suppression

15
Q

Why are patients who are taking chronic steroids more susceptible to infection?

A

Associated immune suppression

16
Q

When are cortisol levels drawn for the dexamethasone suppression test and why?

A

In the morning; this is when cortisol levels should be at the highest

17
Q

Which diuretic is used as a treatment for hyperaldosteronism?

A

Spironolactone, a K+-sparing diuretic that works as an aldosterone antagonist

18
Q

What is the cause of Conns syndrome?

A

An aldosterone-secreting tumor

19
Q

A patient has hypertension, hypokalemia, metabolic alkalosis, and a low plasma renin level; what is the likely diagnosis?

A

Conns syndrome

20
Q

A patient has hypertension, hypokalemia, metabolic alkalosis, and a high plasma renin level; what is the likely diagnosis?

A

Secondary hyperaldosteronism

21
Q

Name five causes of secondary hyperaldosteronism.

A

Renal artery stenosis, chronic renal failure, congestive heart failure, cirrhosis, and nephrotic syndrome

22
Q

Why is secondary hyperaldosteronism associated with high plasma renin levels?

A

All the causes of secondary hyperaldosteronism cause the kidney to perceive a low intravascular volume state, causing up-regulation of the renin-angiotensin pathway

23
Q

Which hormones are deficient in patients with Addisons disease?

A

Cortisol and aldosterone

24
Q

What pathologic findings would be expected in the adrenal glands of a patient with Addisons disease?

A

Adrenal Atrophy affecting All three cortical divisions and Absence of hormone production

25
Q

Name three findings associated with Addisons disease (primary adrenal insufficiency).

A

Hypotension, skin hyperpigmentation, hyperkalemia

26
Q

Is primary or secondary hypoaldosteronism associated with skin hyperpigmentation?

A

Primary

27
Q

Is low adrenocorticotropic hormone production associated with primary or secondary hypoaldosteronism?

A

Secondary

28
Q

Why is skin pigmentation a finding of Addisons?

A

In Addisons, there is increased adrenocorticotropic hormone; proopiomelanocortin is the precursor of adrenocorticotropic hormone and melanocyte-stimulating hormone; melanocyte-stimulating hormone leads to skin hyperpigmentation

29
Q

How is primary adrenal insufficiency distinguished from secondary adrenal insufficiency?

A

Secondary adrenal insufficiency has decreased adrenocorticotropic hormone, no skin hyperpigmentation, and no hyperkalemia

30
Q

What processes can cause primary adrenal insufficiency?

A

Atrophy or destruction by autoimmune disease, tuberculosis infection, or metastatic malignancy

31
Q

A patient with meningococcal septicemia suddenly becomes severely hypotensive, with disseminated intravascular coagulation and endotoxic shock; what is the likely diagnosis?

A

Waterhouse-Friderichsen syndrome, or acute adrenocortical insufficiency caused by adrenal hemorrhage

32
Q

From what cells does a pheochromocytoma develop?

A

Chromaffin cells of the adrenal medulla, which are of neural crest origin

33
Q

Based on a history suggestive of pheochromocytoma, you order serum and urine tests for confirmation; what would be consistent with this diagnosis?

A

Increased plasma catecholamines and urinary vanillylmandelic acid

34
Q

List three genetic syndromes that are associated with pheochromocytoma.

A

Multiple endocrine neoplasia types IIA and IIB, neurofibromatosis

35
Q

What category of drugs is often used to treat pheochromocytoma?

A

-Antagonists

36
Q

Why is phenoxybenzamine a good choice in the treatment of pheochromocytoma?

A

It is a nonselective, irreversible -blocker

37
Q

What are five common symptoms associated with pheochromocytoma?

A

Pressure (elevated blood pressure), Pain (headache), Perspiration, Palpitations (tachycardia), Pallor (remember: the 5 Ps)

38
Q

List the six components of "the pheochromocytoma rule of tens."

A

10% malignant, 10% bilateral, 10% extra-adrenal, 10% calcify, 10% kids, 10% familial

39
Q

What characteristic of pheochromocytoma distinguishes it from chronic, poorly controlled hypertension?

A

Symptoms occur in "spells" and are thus relapsing and remitting

40
Q

From which two amino acids are catecholamines synthesized?

A

Phenylalanine and tyrosine

41
Q

The most common adrenal tumor is _____ in adults and _____ in children.

A

Pheochromocytoma; neuroblastoma

42
Q

Where in the body can a neuroblastoma develop?

A

Anywhere along the sympathetic chain

43
Q

What product is increased in the urine of children with neuroblastoma?

A

Homovanillic acid (a breakdown product of dopamine)

44
Q

What oncogene is associated with neuroblastoma?

A

N-myc

45
Q

How do hypo- and hyperthyroidism each affect temperature tolerance?

A

Hypothyroidism causes cold intolerance; hyperthyroidism causes heat intolerance

46
Q

How do hypo- and hyperthyroidism each affect body weight?

A

Hypothyroidism causes weight gain; hyperthyroidism causes weight loss

47
Q

How do hypo- and hyperthyroidism each affect bowel movements?

A

Hypothyroidism causes constipation; hyperthyroidism causes diarrhea

48
Q

What cardiac symptoms can hyperthyroidism cause?

A

Chest pain and palpitations

49
Q

Which serologic marker is a sensitive test for primary hypothyroidism?

A

Elevated thyroid-stimulating hormone

50
Q

A patient is lethargic and has swelling in the face and periorbital region; you diagnose myxedema resulting from what condition?

A

Hypothyroidism

51
Q

How do hypo- and hyperthyroidism each affect the skin?

A

Hypothyroidism causes dry, cool skin; hyperthyroidism causes warm, moist skin

52
Q

How do hypo- and hyperthyroidism each affect the hair?

A

Hypothyroidism causes coarse, brittle hair; hyperthyroidism causes fine hair

53
Q

What potentially fatal cardiac process is hyperthyroidism known to induce?

A

Arrhythmia

54
Q

What are the lab findings in hypothyroidism?

A

Elevated thyroid-stimulating hormone with a low total T4, free T4, and T3 uptake

55
Q

What are the lab findings in hyperthyroidism?

A

Decreased thyroid-stimulating hormone with elevated total T4, free T4, and T3 uptake

56
Q

What is the most common cause of hypothyroidism?

A

Hashimotos thyroiditis, an autoimmune disorder

57
Q

In the presence of hypothyroidism, what historical and physical exam findings would be consistent with Hashimotos thyroiditis?

A

Hashimotos thyroiditis follows a slow course and produces a moderately enlarged, nontender thyroid

58
Q

Describe the course of Hashimotos thyroiditis.

A

A slow course; it can have an initial period of hyperthyroidism before hypothyroidism due to follicular rupture causing thyrotoxicosis

59
Q

What histologic findings are suggestive of Hashimotos thyroiditis?

A

A lymphocytic infiltrate with germinal centers and Hürthle cells

60
Q

Which two autoantibodies are associated with Hashimotos thyroiditis?

A

Antimicrosomal antibodies and antithyroglobulin antibodies

61
Q

What condition is a result of severe fetal hypothyroidism?

A

Cretinism (meaning "Christlike," these children were considered so mentally retarded as to be incapable of sinning)

62
Q

What are causes of sporadic congenital hypothyroidism?

A

Defect in T4 formation or developmental failure in thyroid formation (congenital hypothyroidism)

63
Q

While traveling in China, you learn that there is a high prevalence of cretinism; what intervention would decrease the prevalence of this disease?

A

This is likely endemic cretinism, found wherever endemic goiter occurs; it could be treated by dietary iodine supplementation

64
Q

What physical exam findings would suggest congenital hypothyroidism in an infant?

A

Pot belly, protruding umbilicus, pale skin, and a puffy face with protuberant tongue

65
Q

Following a flu-like illness, a patient is found to be hypothyroid and to have a tender thyroid gland; what is the prognosis?

A

This is most consistent with subacute thyroiditis, which has a self-limited course

66
Q

Name four findings, other than hypothyroidism, associated with subacute (de Quervains) thyroiditis.

A

Elevated erythrocyte sedimentation rate, jaw pain, early inflammation, and a tender thyroid gland

67
Q

What are histological findings of subacute (de Quervains) thyroiditis?

A

Granulomatous inflammation

68
Q

What is the pathophysiology of Reidels thyroiditis?

A

Thyroid tissue is replaced by fibrous tissue

69
Q

A patient with hypothyroidism has a fixed, hard (rock-like), painless goiter; what is the likely diagnosis?

A

Riedels thyroiditis

70
Q

What is the pathophysiology of Graves disease?

A

It is an autoimmune disorder associated with thyroid-stimulating hormone receptor antibodies that stimulate thyroid hormone release

71
Q

What physical exam findings would suggest that Graves disease is the cause of a case of hyperthyroidism?

A

Exophthalmos, pretibial myxedema, diffuse goiter

72
Q

When does Graves disease most often present?

A

During stress (eg, childbirth)

73
Q

What is a potentially fatal complication of hyperthyroidism?

A

A stress-induced catecholamine surge, which can lead to death by cardiac arrhythmia

74
Q

What type of hypersensitivity reaction is Graves disease?

A

Type II hypersensitivity

75
Q

A patient with hyperthyroidism has a thyroid scan that shows several highly active nodules; what is the diagnosis?

A

Toxic multinodular goiter, in which patches of follicular cells work independently of thyroid-stimulating hormone

76
Q

On physical exam of a 40-year-old woman you find protruding eyes (shown here) and a goiter. What do you expect on examination of her legs?

A

Pretibial myxedema; exophthalmos, diffuse goiter, and pretibial myxedema are three physical findings of Graves' disease

77
Q

A man with thyroid-stimulating hormone level of 0.2 mIU/L and free T4 of 14 mIU/L has the thyroid biopsy shown. What is the Dx?

A

Toxic multinodular goiter, in which patches of follicular cells work independently of thyroid-stimulating hormone

78
Q

CT of a man shows lesions indicating renal osteodystrophy. In the image, what letter best indicates his level of calcium and PTH?

A

(A) secondary hyperparathyroidism due to chronic renal failure

79
Q

A man with renal stones has bone pain. He has increased urine CAMP. In the image, what letter best indicates his level of calcium and PTH?

A

(C) primary hyperparathyroidism (stones, bones, and groans)

80
Q

A man with DiGeorge syndrome presents to your office. In the image, what letter best indicates his levels of calcium and PTH?

A

(B) hypoparathyroidism due to DiGeorge syndrome