Manage bone metastases in pheochromocytoma and paraganglioma
STEP 1 — Gather Information
Collect imaging confirming bone metastases (bone scan, MRI, CT, or PET), assess for spinal cord compression symptoms (progressive back pain, neurologic deficit, bowel/bladder dysfunction), check serum calcium, alkaline phosphatase, and performance status; then proceed to evaluate for spinal cord compression.
STEP 2 — Rule In / Rule Out
Determine if spinal cord compression symptoms are present: if yes, proceed to urgent MRI and high-dose steroids; if no, assess for other skeletal-related events (pain, fracture, hypercalcemia) and proceed to classification.
STEP 3 — Classify or Stratify
Classify bone metastasis by location (spine vs. non-spine) and stability (mechanically unstable vs. stable) based on imaging; if unstable spine or neurologic deficit, proceed to urgent intervention; if stable, proceed to decide on local therapy and bone-modifying agents.
STEP 4 — Decide
For spinal cord compression: administer high-dose dexamethasone and obtain urgent MRI; if confirmed, recommend external beam radiation therapy (± surgery) similar to solid cancers; for stable bone metastases: offer external radiation therapy or surgical stabilization; consider bone-modifying agents (e.g., zoledronic acid, denosumab) for skeletal-related event prevention regardless of location.
Clinical Guardrails / Mimics / Pitfalls
Do not delay imaging or steroids for suspected spinal cord compression; avoid bone-modifying agents as sole treatment for mechanically unstable lesions; do not use NSAIDs as primary analgesic in hypertensive PPGL without alpha-blockade; avoid external radiation without prior alpha-blockade if catecholamine excess is uncontrolled.
Concrete Clinical Example
A 58-year-old with known SDHB-mutated PPGL presents with worsening thoracic back pain and leg weakness. MRI shows T8 vertebral body metastasis with epidural cord compression. After dexamethasone and alpha-blockade, urgent SBRT to 24 Gy in 2 fractions is performed; zoledronic acid is started post-radiation for SRE prevention.
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