General Surgery Board Review Endocrine Surgery 2 — Questions and Answers
Question 1: A parathyroid adenoma is confirmed by concordant sestamibi scan and ultrasound. Which is the preferred surgical approach with intraoperative biochemical confirmation?
- Bilateral four-gland exploration
- Minimally invasive parathyroidectomy with intraoperative PTH monitoring (Correct answer)
- Endoscopic bilateral neck exploration
- Removal of all four glands with autotransplantation
Correct answer: Minimally invasive parathyroidectomy with intraoperative PTH monitoring
Minimally invasive parathyroidectomy with intraoperative PTH monitoring is preferred when imaging is concordant; a >50% drop in PTH from baseline at 10 minutes post-excision confirms cure (Miami criterion).
Question 2: Which MEN syndrome includes medullary thyroid carcinoma, pheochromocytoma, AND mucosal/intestinal ganglioneuromas with marfanoid habitus?
- MEN type 1 (Werner syndrome)
- MEN type 2A (Sipple syndrome)
- MEN type 2B (Correct answer)
- Von Hippel-Lindau syndrome
Correct answer: MEN type 2B
MEN2B is caused by a RET codon 918 mutation and includes MTC, pheochromocytoma, mucosal neuromas of the lips and tongue, and marfanoid habitus; it lacks the hyperparathyroidism seen in MEN2A.
Question 3: Before operating on an adrenal incidentaloma, which condition MUST be excluded first to prevent a life-threatening intraoperative crisis?
- Subclinical hypercortisolism
- Pheochromocytoma (Correct answer)
- Primary aldosteronism
- Non-functioning adrenal adenoma
Correct answer: Pheochromocytoma
Pheochromocytoma must be ruled out with plasma/urine metanephrines before any adrenal surgery, as unrecognized pheochromocytoma can cause a fatal hypertensive crisis during anesthesia induction.
Question 4: A patient has hypertension, hypokalemia, metabolic alkalosis, and an elevated aldosterone-to-renin ratio with a 1.8 cm right adrenal adenoma on CT. What is the diagnosis?
- Pheochromocytoma
- Primary aldosteronism (Conn's syndrome) (Correct answer)
- Cushing's syndrome
- Adrenocortical carcinoma
Correct answer: Primary aldosteronism (Conn's syndrome)
Primary aldosteronism (Conn's syndrome) presents with hypertension, hypokalemia, metabolic alkalosis, elevated aldosterone, and suppressed renin; a unilateral adenoma is confirmed by adrenal vein sampling.
Question 5: What is the correct sequence of preoperative pharmacologic preparation for a patient with pheochromocytoma scheduled for adrenalectomy?
- Beta-blockade alone for 2 weeks
- Alpha-blockade first, then beta-blockade if needed, over 10-14 days (Correct answer)
- Calcium channel blockers alone
- No pharmacologic preparation is required
Correct answer: Alpha-blockade first, then beta-blockade if needed, over 10-14 days
Alpha-blockade (phenoxybenzamine) must precede beta-blockade; initiating beta-blockade first leaves alpha receptors unopposed, potentially causing paradoxical severe hypertension.
Question 6: Which zone of the adrenal cortex is the exclusive site of aldosterone synthesis?
- Zona glomerulosa (Correct answer)
- Zona fasciculata
- Zona reticularis
- Adrenal medulla
Correct answer: Zona glomerulosa
The zona glomerulosa is the outermost cortical layer and the sole site of aldosterone synthesis, regulated primarily by the renin-angiotensin-aldosterone system and serum potassium.
Question 7: Cortisol is elevated and fails to suppress with low-dose (1 mg) dexamethasone, but suppresses >50% with high-dose (8 mg) dexamethasone. What is the most likely etiology of Cushing's syndrome?
- Adrenal cortical adenoma
- Ectopic ACTH production (e.g., small cell lung cancer)
- Pituitary ACTH-secreting adenoma (Cushing's disease) (Correct answer)
- Adrenocortical carcinoma
Correct answer: Pituitary ACTH-secreting adenoma (Cushing's disease)
Suppression with high-dose but not low-dose dexamethasone indicates pituitary-dependent Cushing's disease; adrenal tumors and ectopic ACTH sources are autonomous and fail to suppress with either dose.
General Surgery Board Review Endocrine Surgery 2
A parathyroid adenoma is confirmed by concordant sestamibi scan and ultrasound.
Which is the preferred surgical approach with intraoperative biochemical confirmation?