A 42-year-old woman from rural Maharashtra presents with episodic severe headaches, profuse sweating, and palpitations for 3 months. Her blood pressure is 168/104 mmHg at rest, with a heart rate of 98 bpm. During an episode, BP rises to 210/130 mmHg with tremor and chest tightness. Serum electrolytes are normal. Plasma free metanephrines are elevated at 4.2 times the upper limit of normal (reference <0.9 nmol/L). CT abdomen shows a 3.5 cm left adrenal mass with heterogeneous enhancement. What is the most appropriate next step in management?

Explanation

## Diagnosis & Pathophysiology **Key Point:** Pheochromocytoma is a catecholamine-secreting tumor of chromaffin cells. The classic triad is episodic headaches, profuse sweating, and palpitations with paroxysmal hypertension. ## Diagnostic Confirmation This patient has: - Classic clinical presentation (episodic symptoms with severe hypertension) - Elevated plasma free metanephrines (>4× upper limit of normal) — **gold standard diagnostic test** [cite:Harrison 21e Ch 405] - Imaging confirmation: CT showing left adrenal mass **High-Yield:** Plasma free metanephrines have 96% sensitivity and 89% specificity for pheochromocytoma. A single elevated result in a symptomatic patient is diagnostic. ## Management Algorithm ```mermaid flowchart TD A[Pheochromocytoma confirmed]:::outcome --> B[Alpha-blockade first]:::action B --> C[Phenoxybenzamine or doxazosin]:::action C --> D[Target: BP control + symptom relief]:::action D --> E[Add beta-blocker AFTER alpha-blockade]:::action E --> F[Surgical resection planned]:::action F --> G[Intraoperative hemodynamic stability]:::outcome ``` ## Why Alpha-Blockade FIRST? 1. **Catecholamine-induced vasoconstriction** causes severe hypertension and coronary vasospasm risk 2. **Alpha-blockade reverses peripheral vasoconstriction** → BP control and symptom relief 3. **Beta-blockade alone is CONTRAINDICATED** — unopposed alpha-mediated vasoconstriction worsens hypertension and causes hypertensive crisis 4. **Phenoxybenzamine** (non-selective, irreversible alpha-blocker) is preferred; target BP <160/100 mmHg 5. **Beta-blocker added only after adequate alpha-blockade** to control reflex tachycardia **Clinical Pearl:** The mnemonic **"Alpha FIRST, Beta SECOND"** prevents the catastrophic error of giving beta-blockers alone. ## Preoperative Workup - MIBG scintigraphy or PET-CT is performed **after** biochemical confirmation and imaging, to detect metastases (if suspected) — but NOT the immediate next step in a patient with localized adrenal disease on CT - Genetic testing (RET, SDH, VHL, NF1) if familial syndrome suspected or young age **High-Yield:** Approximately 30% of pheochromocytomas are hereditary (MEN2, NF1, VHL, SDH mutations).