Source / episode info
- **Episode:**192
- **Title:**Divine Intervention Episode 192 – Updated USMLE Step 1 Endocrine Review Series 2 (Adrenals, complete).
- **Published:**2019-12-12
- Source:Episode page
One-liner
This episode provides a comprehensive review of hypercortisolism workup (Cushing syndrome), primary and secondary mineralocorticoid excess (Conn Syndrome), adrenal tumor differentiation (Neuroblastoma vs. WHOMs), and the management principles for pheochromocytoma.
High-yield summary
- Cushing Syndrome Workup: Initial screening involves elevated 24-hour urinary free cortisol or failure to suppress morning cortisol with low-dose dexamethasone. ACTH levels determine if the cause is adrenal (low ACTH) or pituitary/ectopic (high ACTH).
- Primary Hyperaldosteronism (Conn Syndrome): Characterized by resistant hypertension, hypokalemia, metabolic alkalosis, and an elevated plasma Aldosterone/Plasma Renin Ratio (ARR). Diagnosis confirmation requires failure to suppress aldosterone with saline infusion.
- Neuroblastoma vs. WHOMs: Neuroblastomas are neurogenic tumors that classically cross the midline and tend to be calcified; they present with paraneoplastic syndromes like oculo-motor clonus and myoclonus. WHOMs do not typically cross the midline.
- Pheochromocytoma Management: Preoperative management requires blocking alpha receptors first (e.g., Phenoxybenzamine) before administering beta-blockers to prevent precipitous blood pressure drops.
- Adrenal Tumors: Adrenal adenomas are often non-functional, while adrenal carcinomas usually hypersecrete multiple hormones (cortisol, aldosterone, sex steroids).
Learning objectives
- Differentiate the diagnostic workup flow for Cushing syndrome based on ACTH levels.
- Identify the classic biochemical triad (hypertension, hypokalemia, metabolic alkalosis) associated with mineralocorticoid excess.
- Distinguish between primary and secondary causes of hyperaldosteronism using plasma renin activity measurements.
- Recognize the characteristic physical exam findings and imaging features that differentiate neuroblastoma from WHOMs.
- Outline the critical sequence for pre-operative management of pheochromocytoma.
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