Physician Assistant Endocrine System Disorders 2 — Questions and Answers
Question 1: A 40-year-old woman presents with moon facies, central obesity, purple striae, and easy bruising. 24-hour urinary free cortisol is markedly elevated. What is the most likely diagnosis?
- Addison's disease
- Cushing's syndrome (Correct answer)
- Primary hyperaldosteronism
- Acromegaly
Correct answer: Cushing's syndrome
Cushing's syndrome results from chronic excess cortisol and presents with moon facies, buffalo hump, purple striae, and central obesity.
Question 2: Which of the following is the most common overall cause of Cushing's syndrome?
- Adrenal adenoma
- Ectopic ACTH production
- Exogenous corticosteroid use (Correct answer)
- Pituitary adenoma (Cushing's disease)
Correct answer: Exogenous corticosteroid use
Exogenous corticosteroid use is the most common cause of Cushing's syndrome overall, making it iatrogenic in most cases.
Question 3: A 35-year-old woman presents with weakness, fatigue, hyperpigmentation, hyponatremia, and hyperkalemia. Cortisol is low and ACTH is markedly elevated. What is the most likely diagnosis?
- Cushing's disease
- Addison's disease (Correct answer)
- Secondary adrenal insufficiency
- Primary hyperaldosteronism
Correct answer: Addison's disease
Addison's disease (primary adrenal insufficiency) features elevated ACTH causing hyperpigmentation, with low cortisol, hyponatremia, and hyperkalemia.
Question 4: A 45-year-old man has resistant hypertension despite three antihypertensives and persistent hypokalemia. The aldosterone-to-renin ratio is markedly elevated. What is the most likely diagnosis?
- Pheochromocytoma
- Cushing's syndrome
- Primary hyperaldosteronism (Conn's syndrome) (Correct answer)
- Renovascular hypertension
Correct answer: Primary hyperaldosteronism (Conn's syndrome)
Primary hyperaldosteronism causes autonomous aldosterone excess, resulting in resistant hypertension, hypokalemia, and an elevated aldosterone-to-renin ratio.
Question 5: A 30-year-old woman presents with galactorrhea, amenorrhea, and bitemporal headaches. MRI shows a pituitary mass and prolactin is 160 ng/mL. What is the first-line treatment?
- Transsphenoidal surgical resection
- Dopamine agonist (cabergoline or bromocriptine) (Correct answer)
- Cranial radiation therapy
- Leuprolide acetate
Correct answer: Dopamine agonist (cabergoline or bromocriptine)
Dopamine agonists are the first-line treatment for prolactinomas, as they suppress prolactin secretion and reduce tumor size.
Question 6: Which of the following is the most appropriate initial biochemical test to screen for pheochromocytoma?
- CT scan of the abdomen
- Plasma free metanephrines or 24-hour urine fractionated metanephrines (Correct answer)
- Clonidine suppression test
- Serum cortisol level
Correct answer: Plasma free metanephrines or 24-hour urine fractionated metanephrines
Plasma free metanephrines or 24-hour urine fractionated metanephrines are the preferred biochemical tests for screening pheochromocytoma due to high sensitivity.
Question 7: A 35-year-old man presents with coarse facial features, enlarged hands and feet, headaches, and bitemporal hemianopsia. IGF-1 is markedly elevated. What is the most likely diagnosis?
- Cushing's disease
- Acromegaly (Correct answer)
- Prolactinoma
- Gigantism
Correct answer: Acromegaly
Acromegaly is caused by excess GH after epiphyseal closure, leading to coarse acral features and elevated IGF-1; a pituitary tumor causes the visual field defect.
Physician Assistant Endocrine System Disorders 2
A 40-year-old woman presents with moon facies, central obesity, purple striae, and easy bruising. 24-hour urinary free cortisol is markedly elevated.
What is the most likely diagnosis?