Adrenal Gland Pathology

Question 1

Pt is a 40yoF with PMH of type 2 diabetes mellitus x 6mo presenting with central weight gain x 3mo, loss of libido, and HTN. PE is notable for roundish face, supraclavicular fat pads, violaceous striae, and myopathy. What should you be thinking?

Answer 1

Cushing Syndrome (hypercortisolism) - signs include diabetes/HTN, abnormal fat deposition (central obesity, moon face, fat pads), violaceous striae + easy bruising, myopathy, osteoporosis, frequent infections, psychiatric abnormalities

Question 2

what are some causes of pseudo-Cushing syndrome (non-neoplastic hypercortisolemia)?

Answer 2

overexercise, eating disorders, uncontrolled diabetes, sleep apnea, alcoholism, stress, extreme obesity

Question 3

ectopic ACTH syndrome can be caused by which type of lung cancer?

Answer 3

small cell lung cancer - ectopic ACTH secretion presents as etiology of Cushing Syndrome

this is the most common tumor to cause ectopic ACTH secretion

Question 4

what causes Cushing Disease?

Answer 4

pituitary ACTH over-secretion —> overproduction of adrenal cortisol

labs will show HIGH ACTH and HIGH cortisol

Question 5

how can the following be used to screen for Cushing Syndrome?
a. 24h urinary free cortisol (UFC)
b. overnight dexamethasone suppression test (low dose DST)
c. late-night salivary cortisol (LNSC)

Answer 5

a. 24h urinary free cortisol (UFC): measures gross overproduction of cortisol across a period of time

b. overnight dexamethasone suppression test (low dose DST): dynamic test that assesses HPA axis responsiveness to glucocorticoids, detecting autonomous cortisol secretion

c. late-night salivary cortisol (LNSC): measures free cortisol at a time when it should be at its lowest level, detecting loss of circadian rhythm of secretion

Question 6

how can dexamethasone suppression test be used to evaluate whether Cushing Syndrome is ACTH dependent or independent?

Answer 6

Dexamethasone suppression test measures whether adrenocorticotrophic hormone (ACTH) secretion by the pituitary can be suppressed

if suppressed —> ACTH-independent (exogenous glucocorticoids or adrenal tumor)

if elevated —> ACTH-dependent… then use a higher dose and assess again —> still elevated = ectopic ACTH secretion / adequately suppressed = Cushing Disease (pituitary)

Question 7

Pt 42yo F is presenting with weight loss/fatigue x 6mo, anorexia and frequent N/V, salt craving, and loss of pubic hair. PE is notable for hyperpigmentation and hypotension. Labs notable for fasting hypoglycemia, hyponatremia, hyperkalemia, azotemia, and metabolic acidosis. What is the most likely diagnosis?

Answer 7

Addison Disease: primary adrenal insufficiency

cortisol deficiency - weight loss, fatigue, weakness, anorexia, N/V, fasting hypoglycemia, decreased responsiveness to catecholamines

mineralocorticoid deficiency (primary cause only) - inability to conserve Na+/ excrete K+, dehydration, hypotension/ decreased CO, azotemia, metabolic acidosis

lack of androgens - lack of axillary/ pubic hair

excess of ACTH (primary cause only) - hyperpigmentation (ACTH and alpha-MSH both made from POMC)

Question 8

Waterhouse-Friderichsen Syndrome

Answer 8

adrenal hemorrhage due to sepsis —> primary adrenal insufficiency

classically due to Neisseria meningitidis —> rapidly progressive hypotension/shock, DIC and purpura

Question 9

Conn Syndrome

Answer 9

aka primary mineralocorticoid excess: presents with HTN, hypokalemia, metabolic alkalosis

labs show HIGH aldosterone + HIGH aldosterone:PRA ratio

etiologies include bilateral adrenal hyperplasia, aldosterone-producing adrenal adenoma, adrenal carcinoma

tx: spironolactone (aldosterone antagonist, K+ sparing diuretic)

Question 10

what does the triad of pain (headache), perspiration, and palpitations suggest?

Answer 10

Pheochromocytoma: tumor derived from chromaffin cells of adrenal medulla (arise from neural crest), can secrete epinephrine/ norepinephrine/ dopamine

ALL patients should be treated with surgery