dromlakhani Select initial screening test for pheochromocytoma and paraganglioma
STEP 1 — Gather Information
Collect clinical suspicion (paroxysmal hypertension, adrenal incidentaloma, family history of PPGL), assess renal function for urine creatinine correction, review medications/foods that affect catecholamines, and determine patient ability to fast and remain supine for plasma testing. → Proceed to step 2.
STEP 2 — Rule In / Rule Out
Rule out random urinary fractionated metanephrines if severe renal impairment (eGFR <30 mL/min/1.73m²) makes creatinine correction unreliable; if not ruled out, urine test remains an option. → Proceed to step 3.
STEP 3 — Classify or Stratify
If urine test is available and patient prefers non‑fasting sample, select random urinary fractionated metanephrines (creatinine corrected); otherwise, if plasma‑free fractionated metanephrines assay is accessible and patient can fast 30 min supine, select plasma test; else select blood fractionated catecholamines. → Proceed to step 4.
STEP 4 — Decide
Order the selected screening test and apply the diagnostic cutoff: value >3× the upper limit of normal (after creatinine correction for urine) indicates a positive screen requiring confirmatory testing. → End.
Clinical Guardrails / Mimics / Pitfalls
Avoid testing after recent intake of caffeine, bananas, citrus, vanilla, cheese, red wine, or drugs such as TCAs, levodopa, decongestants, or MAO inhibitors; do not interpret borderline results without repeat testing under standardized conditions; note that plasma‑free fractionated metanephrines is limited to one measurement under Japanese health insurance and requires strict collection (fasting, 20‑30 min supine, immediate freezing) to limit false positives.
Concrete Clinical Example
A 46‑year‑old woman with episodic headaches, diaphoresis, and blood pressure spikes to 190/100 mm Hg has an adrenal incidentaloma on abdominal CT; renal function normal, no interfering meds, and prefers a non‑fasting urine sample; order random urinary fractionated metanephrines creatinine corrected.
Source: Japan Endocrine Society Clinical Practice Guideline for the Diagnosis and Management of Pheochromocytoma and Paraganglioma 2025, Japan Endocrine Society, 2025, doi:10.1507/endocrj.EJ25-0165
TODO: consider adding scripts/calc.py for the ata-ppgl-screening-test-selection calculator