| name | ppgl-metastasis-risk-assessment-clinical |
| description | Assesses metastasis risk in PPGL using clinical factors such as age at diagnosis, tumor size, catecholamine secretion pattern, and tumor location. Indicated for newly diagnosed PPGL patients requiring risk stratification, evaluating metastatic potential, or pre-treatment assessment of aggressiveness. |
PPGL Metastasis Risk Assessment Using Clinical Factors
STEP 1 — Gather Information
Collect age at diagnosis, tumor size (cm) on imaging, catecholamine secretion pattern (adrenaline vs noradrenaline dominance via plasma free metanephrines/normetanephrines or 24‑h urine metabolites), and tumor location (adrenal PCC vs extra‑adrenal PGL, noting abdominal or head/neck PGL).
STEP 2 — Rule In / Rule Out
Determine if any high‑risk clinical feature is present: age < 40 years, tumor ≥ 4 cm, noradrenaline dominance, or PGL location (extra‑adrenal). If none are present, classify as low risk; if at least one is present, proceed to stratification.
STEP 3 — Classify or Stratify
Count the number of high‑risk features present: 1 feature = intermediate risk, 2‑3 features = high risk, ≥4 features = very high risk. Adjust for tumor size thresholds: 4‑7 cm adds one point, > 7 cm adds two points.
STEP 4 — Decide
Low risk: routine biochemical and imaging surveillance per standard follow‑up. Intermediate risk: add SDHB immunostaining on resected tissue or germline SDHB testing, and shorten surveillance interval to 6‑12 months. High/Very high risk: pursue comprehensive genetic panel (SDHB, VHL, RET, etc.), consider early functional imaging (18F‑FDG PET/CT), and discuss multidisciplinary planning for possible metastatic workup.
Clinical Guardrails / Mimics / Pitfalls
Do not rely solely on clinical factors; histopathological confirmation (SDHB loss) and genetic testing are required for definitive risk stratification. Avoid overestimating risk in elderly patients with small tumors (< 4 cm) noradrenaline‑secreting PCCs, which have low metastatic potential. Remember that head‑and‑neck PGLs, despite being extra‑adrenal, carry a low metastasis rate (< 5 %) and should not be upstaged based on location alone.
Concrete Clinical Example
A 35‑year‑old patient presents with a 5 cm abdominal PGL, plasma normetanephrine markedly elevated (noradrenaline dominance), and no family history. Two high‑risk features (age < 40, tumor ≥ 4 cm, noradrenaline dominance) yield high risk. Proceed to SDHB germline testing and schedule 18F‑FDG PET/CT at 6‑month intervals.
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
