Endocrine - Pathology Part 1 Flashcards
A 30-year-old male comes to clinic with central obesity and purple striae across teh abdomen. What is the likely diagnosis?
Cushing’s disease, which constitutes 70% of cases of Cushing’s syndrome
A patient with Cushings syndrome has an increased adrenocorticotropic hormone level; what are two mechanisms of increased adrenocorticotropic hormone production?
Overproduction of adrenocorticotropic hormone by the pituitary and overproduction of adrenocorticotropic hormone by an ectopic site (such as in small-cell lung cancer)
A patient with Cushings syndrome has a decreased adrenocorticotropic hormone level; what are two mechanisms of increased cortisol production with low adrenocorticotropic hormone levels?
Overproduction of cortisol by the adrenal cortex or administration of exogenous cortisol
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?
High
A patient is diagnosed with primary adrenal cortical hyperplasia. Will this patients adrenocorticotropic hormone level be high or low?
Low
What is the effect of long-term steroid administration on adrenocorticotropic hormone?
Suppression of the hypothalamic-pituitary-adrenal axis causing low adrenocorticotropic hormone levels
What is Cushings disease?
An adrenocorticotropic hormone-hypersecreting primary pituitary adenoma
What are the results of a low dose dexamethasone suppression test in a healthy person?
Decreased cortisol level; dexamethasone decreases adrenocorticotropic hormone secretion by negative feedback leading to decreased cortisol levels
What results would you expect after a dexamethasone suppression test in the setting of an adrenocorticotropic hormone-producing pituitary tumor?
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
Would cortisol levels be high or low after a high-dose dexamethasone suppression test in a patient with an ectopic adrenocorticotropic hormone-producing tumor?
High; the secretory activity of this tumor is independent of negative feedback
Would cortisol levels be high or low after a high-dose dexamethasone suppression test in a patient with a cortisol-producing tumor?
High; the secretory activity of this tumor is independent of negative feedback
What findings are indicative of Cushings syndrome?
Hypertension, weight gain, moon facies, truncal obesity, buffalo hump, hyperglycemia (insulin resistance), skin changes, osteoporosis, amenorrhea, and immune suppression
Why are patients who are taking chronic steroids more susceptible to infection?
Associated immune suppression
When are cortisol levels drawn for the dexamethasone suppression test and why?
In the morning; this is when cortisol levels should be at the highest
Which diuretic is used as a treatment for hyperaldosteronism?
Spironolactone, a K+-sparing diuretic that works as an aldosterone antagonist
What is the cause of Conns syndrome?
An aldosterone-secreting tumor
A patient has hypertension, hypokalemia, metabolic alkalosis, and a low plasma renin level; what is the likely diagnosis?
Conns syndrome
A patient has hypertension, hypokalemia, metabolic alkalosis, and a high plasma renin level; what is the likely diagnosis?
Secondary hyperaldosteronism
Name five causes of secondary hyperaldosteronism.
Renal artery stenosis, chronic renal failure, congestive heart failure, cirrhosis, and nephrotic syndrome
Why is secondary hyperaldosteronism associated with high plasma renin levels?
All the causes of secondary hyperaldosteronism cause the kidney to perceive a low intravascular volume state, causing up-regulation of the renin-angiotensin pathway
Which hormones are deficient in patients with Addisons disease?
Cortisol and aldosterone
What pathologic findings would be expected in the adrenal glands of a patient with Addisons disease?
Adrenal Atrophy affecting All three cortical divisions and Absence of hormone production
Name three findings associated with Addisons disease (primary adrenal insufficiency).
Hypotension, skin hyperpigmentation, hyperkalemia
Is primary or secondary hypoaldosteronism associated with skin hyperpigmentation?
Primary
Is low adrenocorticotropic hormone production associated with primary or secondary hypoaldosteronism?
Secondary
Why is skin pigmentation a finding of Addisons?
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
How is primary adrenal insufficiency distinguished from secondary adrenal insufficiency?
Secondary adrenal insufficiency has decreased adrenocorticotropic hormone, no skin hyperpigmentation, and no hyperkalemia
What processes can cause primary adrenal insufficiency?
Atrophy or destruction by autoimmune disease, tuberculosis infection, or metastatic malignancy
A patient with meningococcal septicemia suddenly becomes severely hypotensive, with disseminated intravascular coagulation and endotoxic shock; what is the likely diagnosis?
Waterhouse-Friderichsen syndrome, or acute adrenocortical insufficiency caused by adrenal hemorrhage
From what cells does a pheochromocytoma develop?
Chromaffin cells of the adrenal medulla, which are of neural crest origin