| name | pheo-screening-strategy |
| description | First-line screening logic to identify patients who require biochemical testing for Pheochromocytoma or Paraganglioma. Trigger when a clinician asks "who to screen for pheo", "evaluation of adrenal incidentaloma", or "workup for paroxysmal hypertension." |
Pheochromocytoma Screening Strategy
This skill provides the clinical decision criteria for initiating biochemical screening for pheochromocytoma and paraganglioma based on the Endocrine Society Clinical Practice Guidelines.
Step 1 — Identification of High-Risk Clinical Features
Screen for pheochromocytoma if any of the following are present:
-
Paroxysmal Symptoms ("The Spell"):
- Triad of: Episodic headache, sweating, and palpitations.
- Note: The presence of all three in a hypertensive patient has high specificity (>90%).
-
Refractory or Early-Onset Hypertension:
- Drug-resistant hypertension (uncontrolled on ≥3 agents).
- Marked blood glucose lability or paradoxically worsening BP with beta-blockers.
- Hypertension onset at age <20 years.
-
Adrenal Incidentaloma:
- Any adrenal mass discovered on imaging, especially if the unenhanced CT attenuation is >10 Hounsfield Units (HU).
-
Genetic Predisposition:
- Personal or family history of MEN2, NF1, or von Hippel-Lindau (VHL).
- Personal history of a previous glomus tumor or paraganglioma.
Step 2 — Decision: To Screen or Not to Screen?
| Finding Present? | Action |
|---|
| YES to any above | Move to Biochemical Testing (Plasma or 24h Urinary Metanephrines). |
| NO | Pheochromocytoma is unlikely; manage as primary hypertension unless other secondary features emerge. |
Clinical Guardrails
- Do NOT proceed to imaging first. Always obtain biochemical proof before ordering CT or MRI. Imaging first leads to false positives and unnecessary surgeries.
- Beta-Blocker Warning: Never start a beta-blocker (e.g., Propranolol, Atenolol) before establishing alpha-blockade if pheo is suspected, as this can trigger a hypertensive crisis due to unopposed alpha-stimulation.
- Medication Interference: Many drugs (TCAs, Levodopa, Decongestants) can cause false-positive metanephrine elevations. Review the med list before testing.
Source: Lenders JW, et al. Pheochromocytoma and Paraganglioma: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2014;99(6):1915-42. doi: 10.1210/jc.2014-1498
