Endocrine - Pathology (Part 1)

Question 1

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

Answer 1

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

Question 2

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

Answer 2

Papillary carcinoma

Question 3

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

Answer 3

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

Question 4

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

Answer 4

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

Question 5

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

Answer 5

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

Question 6

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?

Answer 6

High

Question 7

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

Answer 7

Low

Question 8

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

Answer 8

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

Question 9

What is Cushings disease?

Answer 9

An adrenocorticotropic hormone-hypersecreting primary pituitary adenoma

Question 10

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

Answer 10

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

Question 11

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

Answer 11

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

Question 12

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

Answer 12

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

Question 13

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

Answer 13

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

Question 14

What findings are indicative of Cushings syndrome?

Answer 14

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

Question 15

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

Answer 15

Associated immune suppression

Question 16

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

Answer 16

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

Question 17

Which diuretic is used as a treatment for hyperaldosteronism?

Answer 17

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

Question 18

What is the cause of Conns syndrome?

Answer 18

An aldosterone-secreting tumor

Question 19

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

Answer 19

Conns syndrome

Question 20

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

Answer 20

Secondary hyperaldosteronism

Question 21

Name five causes of secondary hyperaldosteronism.

Answer 21

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

Question 22

Why is secondary hyperaldosteronism associated with high plasma renin levels?

Answer 22

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

Question 23

Which hormones are deficient in patients with Addisons disease?

Answer 23

Cortisol and aldosterone

Question 24

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

Answer 24

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

Question 25

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

Answer 25

Hypotension, skin hyperpigmentation, hyperkalemia

Question 26

Is primary or secondary hypoaldosteronism associated with skin hyperpigmentation?

Answer 26

Primary

Question 27

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

Answer 27

Secondary

Question 28

Why is skin pigmentation a finding of Addisons?

Answer 28

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

Question 29

How is primary adrenal insufficiency distinguished from secondary adrenal insufficiency?

Answer 29

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

Question 30

What processes can cause primary adrenal insufficiency?

Answer 30

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

Question 31

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

Answer 31

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

Question 32

From what cells does a pheochromocytoma develop?

Answer 32

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

Question 33

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

Answer 33

Increased plasma catecholamines and urinary vanillylmandelic acid

Question 34

List three genetic syndromes that are associated with pheochromocytoma.

Answer 34

Multiple endocrine neoplasia types IIA and IIB, neurofibromatosis

Question 35

What category of drugs is often used to treat pheochromocytoma?

Answer 35

-Antagonists

Question 36

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

Answer 36

It is a nonselective, **irreversible** -blocker

Question 37

What are five common symptoms associated with pheochromocytoma?

Answer 37

**P**ressure (elevated blood pressure), **P**ain (headache), **P**erspiration, **P**alpitations (tachycardia), **P**allor (remember: the **5 P**s)

Question 38

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

Answer 38

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

Question 39

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

Answer 39

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

Question 40

From which two amino acids are catecholamines synthesized?

Answer 40

Phenylalanine and tyrosine

Question 41

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

Answer 41

Pheochromocytoma; neuroblastoma

Question 42

Where in the body can a neuroblastoma develop?

Answer 42

Anywhere along the sympathetic chain

Question 43

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

Answer 43

Homovanillic acid (a breakdown product of dopamine)

Question 44

What oncogene is associated with neuroblastoma?

Answer 44

N-*myc*

Question 45

How do hypo- and hyperthyroidism each affect temperature tolerance?

Answer 45

Hypothyroidism causes cold intolerance; hyperthyroidism causes heat intolerance

Question 46

How do hypo- and hyperthyroidism each affect body weight?

Answer 46

Hypothyroidism causes weight gain; hyperthyroidism causes weight loss

Question 47

How do hypo- and hyperthyroidism each affect bowel movements?

Answer 47

Hypothyroidism causes constipation; hyperthyroidism causes diarrhea

Question 48

What cardiac symptoms can hyperthyroidism cause?

Answer 48

Chest pain and palpitations

Question 49

Which serologic marker is a sensitive test for primary hypothyroidism?

Answer 49

Elevated thyroid-stimulating hormone

Question 50

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

Answer 50

Hypothyroidism

Question 51

How do hypo- and hyperthyroidism each affect the skin?

Answer 51

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

Question 52

How do hypo- and hyperthyroidism each affect the hair?

Answer 52

Hypothyroidism causes coarse, brittle hair; hyperthyroidism causes fine hair

Question 53

What potentially fatal cardiac process is hyperthyroidism known to induce?

Answer 53

Arrhythmia

Question 54

What are the lab findings in hypothyroidism?

Answer 54

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

Question 55

What are the lab findings in hyperthyroidism?

Answer 55

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

Question 56

What is the most common cause of hypothyroidism?

Answer 56

Hashimotos thyroiditis, an autoimmune disorder

Question 57

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

Answer 57

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

Question 58

Describe the course of Hashimotos thyroiditis.

Answer 58

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

Question 59

What histologic findings are suggestive of Hashimotos thyroiditis?

Answer 59

A lymphocytic infiltrate with germinal centers and Hürthle cells

Question 60

Which two autoantibodies are associated with Hashimotos thyroiditis?

Answer 60

Antimicrosomal antibodies and antithyroglobulin antibodies

Question 61

What condition is a result of severe fetal hypothyroidism?

Answer 61

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

Question 62

What are causes of sporadic congenital hypothyroidism?

Answer 62

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

Question 63

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

Answer 63

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

Question 64

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

Answer 64

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

Question 65

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

Answer 65

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

Question 66

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

Answer 66

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

Question 67

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

Answer 67

Granulomatous inflammation

Question 68

What is the pathophysiology of Reidels thyroiditis?

Answer 68

Thyroid tissue is replaced by fibrous tissue

Question 69

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

Answer 69

Riedels thyroiditis

Question 70

What is the pathophysiology of Graves disease?

Answer 70

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

Question 71

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

Answer 71

Exophthalmos, pretibial myxedema, diffuse goiter

Question 72

When does Graves disease most often present?

Answer 72

During stress (eg, childbirth)

Question 73

What is a potentially fatal complication of hyperthyroidism?

Answer 73

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

Question 74

What type of hypersensitivity reaction is Graves disease?

Answer 74

Type II hypersensitivity

Question 75

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

Answer 75

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

Question 76

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?

Answer 76

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

Question 77

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?

Answer 77

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

Question 78

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

Answer 78

(A) secondary hyperparathyroidism due to chronic renal failure

Question 79

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?

Answer 79

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

Question 80

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

Answer 80

(B) hypoparathyroidism due to DiGeorge syndrome