Imaging + Screening
Which type of MRI would be most useful to visualize the kidneys and their fluid structures?
T2 weighted MRI
Which medication lowers cortisol levels by blocking adrenal steroid synthesis rather than acting directly on the pituitary?
A. Pasireotide
B. Cabergoline
C. Ketoconazole
D. Octreotide
E. Pegvisomant
C. Ketoconazole
During surgery, manipulation near the optic chiasm results in postoperative visual changes. Which of the following visual field defects is most likely?
A. Left homonymous hemianopia
B. Bitemporal hemianopia
C. Right inferior quadrantanopia
D. Central scotoma
E. Tunnel vision from retinal ischemia
B. Bitemporal hemianopia
Tertiary hypercortisolism is a result of dysfunction in which organ?
hypothalamus
Which part of the pituitary gland releases ACTH?
anterior pituitary
A patient has weight gain, hypertension, and proximal muscle weakness. Initial evaluation for suspected Cushing syndrome is planned. Which of the following is an appropriate first-line screening test?
A. Pituitary MRI
B. High-dose dexamethasone suppression test
C. 24-hour urinary free cortisol
D. Inferior petrosal sinus sampling
E. CT scan of the adrenal glands
C. 24-hour urinary free cortisol
A patient with Cushing disease cannot undergo surgery. Which medication works by suppressing ACTH release from a pituitary adenoma via somatostatin receptor subtype 5?
A. Octreotide
B. Pasireotide
C. Bromocriptine
D. Metyrapone
E. Spironolactone
B. Pasireotide
Several days after trans-sphenoidal surgery, a patient develops confusion and low serum sodium. Urine osmolality is high. Which complication is most likely?
SIADH
Upregulation of which polypeptide leads to hyperpigmentation of the palmar crease in Cushings?
POMC
Which structure connects the hypothalamus to the pituitary gland?
Infundibulum
What does a partial suppression of cortisol in a dexamethasone suppression test indicate?
pituitary tumor
thrombosis
A patient undergoes successful resection of an ACTH-secreting pituitary adenoma. Immediately postoperatively, she develops fatigue, hypotension, and hypoglycemia.Which of the following best explains this complication?
A. Chronic cortisol excess causes permanent adrenal failure
B. Suppression of normal corticotroph cells leads to transient adrenal insufficiency
C. Increased aldosterone secretion causes electrolyte imbalance
D. Persistent ectopic ACTH production
E. Excess CRH release from the hypothalamus
B. Suppression of normal corticotroph cells leads to transient adrenal insufficiency
ACTH stimulates cortisol synthesis by activating melanocortin-2 receptors on adrenal cortical cells. Which intracellular signaling pathway mediates this effect?
A. Phospholipase C → IP₃/DAG
B. JAK-STAT signaling
C. Adenylate cyclase → cAMP → protein kinase A
D. Tyrosine kinase receptor phosphorylation
E. MAP kinase inhibition
C. Adenylate cyclase → cAMP → protein kinase A
Which hypothalamic nucleus primarily produces corticotropin-releasing hormone (CRH)?
Paraventricular nucleus
Which of the following imaging findings is most consistent with ACTH-dependent Cushing disease?
A. Unilateral adrenal cortical atrophy
B. Bilateral adrenal hyperplasia
C. Adrenal medullary tumor
D. Atrophy of the zona glomerulosa only
E. Single adrenal nodule with low ACTH
B. Bilateral adrenal hyperplasia
Which 2 inflammatory transcription factors are inhibited by glucocorticoids primarily?
NF-κB and AP-1
Immediately after transsphenoidal surgery, a patient develops excessive thirst and passes large volumes of dilute urine. Serum sodium is elevated.
Which of the following structures was most likely affected during surgery?
A. Anterior pituitary corticotroph cells
B. Posterior pituitary or pituitary stalk
C. Cavernous sinus sympathetic fibers
D. Optic chiasm
E. Hypothalamic CRH neurons
B. Posterior pituitary or pituitary stalk
Cortisol causes hypertension in Cushing syndrome primarily because it:
A. Directly increases aldosterone secretion
B. Stimulates renin release
C. Activates mineralocorticoid receptors when present in excess
D. Blocks sodium reabsorption in the kidney
E. Inhibits catecholamine synthesis
C. Activates mineralocorticoid receptors when present in excess
The adrenal cortex and adrenal medulla originate embryologically from which two tissue layers?
Cortex: mesoderm
Medulla: neural ectoderm (neural crest cells)
A 27-year-old man comes to the physician because of a 4-month history of unintentional weight gain, fatigue, and decreased sexual desire. There is no personal or family history of serious illness. His blood pressure is 149/88 mm Hg. Physical examination shows central obesity and abdominal striae. He has a prominent soft-tissue bulge at the dorsum of his neck. Laboratory studies show a 24-hour urinary free cortisol of 200 µg (N < 50) and a morning serum ACTH of 1 pg/mL (N = 7-50). Which of the following tests is most likely to confirm the underlying etiology of this patient's symptoms?
A) CRH stimulation test
B) ACTH stimulation test
C) low-dose dexamethasone suppression test
D) CT scan of abdomen
E) MRI of brain
D) CT scan of abdomen
A 55-year-old man presents with enlarged hands, coarse facial features, joint pain, and excessive sweating. Laboratory evaluation shows elevated IGF-1 and failure of growth hormone suppression after oral glucose testing. MRI shows a pituitary macroadenoma. Surgery is performed, but GH levels remain elevated. He is started on a long-acting injectable medication. Three months later, his diarrhea improves and IGF-1 levels decrease, but ultrasound shows new gallstones. Which of the following best describes the mechanism of this medication?
A. High-affinity binding to SSTR5 causing suppression of ACTH secretion
B. Competitive antagonism of GH receptors in peripheral tissues
C. Activation of SSTR2 leading to inhibition of GH and GI peptide secretion
D. Dopamine D2 receptor agonism reducing prolactin release
E. Direct inhibition of adrenal steroidogenesis
C. Activation of SSTR2 leading to inhibition of GH and GI peptide secretion
A 7-year-old girl is brought to the physician because of a 1-month history of worsening fatigue, loss of appetite, and decreased energy. More recently, she has also had intermittent abdominal pain and nausea. She is at the 50th percentile for height and 15th percentile for weight. Her pulse is 119/min and blood pressure is 85/46 mm Hg. Physical examination shows darkened skin and bluish-black gums. The abdomen is soft and nontender. Serum studies show:
Sodium 133 mEq/L
Potassium 5.3 mEq/L
Bicarbonate 20 mEq/L
Urea nitrogen 16 mg/dL
Creatinine 0.8 mg/dL
Glucose 72 mg/dL
Which of the following is the most appropriate pharmacotherapy?
A Succimer
B Levothyroxine
C Deferoxamine
D Isoniazid + rifampin + pyrazinamide + ethambutol
E Glucocorticoids
F Norepinephrine
E Glucocorticoids
A 47-year-old woman presents with moon facies, abdominal striae, and proximal muscle weakness. Labs reveal:
Elevated ACTH
Elevated cortisol
No suppression with low-dose dexamethasone
No suppression with high-dose dexamethasone
Chest imaging reveals a hilar mass.
Which of the following best explains why high-dose dexamethasone fails to suppress cortisol in this patient?
A. The tumor lacks glucocorticoid receptors
B. ACTH secretion is driven by CRH hypersecretion
C. Cortisol production is independent of ACTH
D. Pituitary corticotrophs are resistant to CRH
E. The adrenal cortex has downregulated steroidogenic enzymes
A. The tumor lacks glucocorticoid receptors
A 36-year-old woman comes to the physician for evaluation of unintentional weight gain of 5.5 kg (12.2 lb) and irregular menstrual cycles over the past 2 months. She does not take any medications. Her blood pressure is 155/85 mm Hg. Physical examination shows central obesity, hyperpigmentation of the palmar creases, and violaceous scarring of the abdomen. Early morning serum cortisol levels are elevated and serum adrenocorticotropic hormone (ACTH) is within the reference range after a low-dose dexamethasone suppression test. A high-dose dexamethasone suppression test shows suppression of ACTH. Further evaluation is most likely to show which of the following findings?
A Atrophy of the pituitary gland
B Benign adenoma of the adrenal medulla
C Nodular hypertrophy of the zona reticularis
D Bilateral hyperplasia of the zona fasciculata
E Unilateral carcinoma of the adrenal cortex
D Bilateral hyperplasia of the zona fasciculata