aside Pheochromocytoma

Case Presentation:

In our morning report at WCH, we discussed a case of a patient presenting with severe hypertension and episodic headaches. Subsequent laboratory investigation and imaging confirmed the presence of a unilateral adrenal mass which was a pheochromocytoma.

Learning Points:

  1. Establishing the diagnosis of hypertension
  2. Recognizing the difference between hypertensive urgency and emergency
  3. Differential diagnosis of secondary hypertension
  4. Diagnosis and management of pheochromocytoma

Establishing the Diagnosis:

CHEP Guidelines

CHEP Dx

Hypertensive Urgency vs Emergency:

  • Urgency=asymptomatic marked BP elevation without target organ damage
  • Emergency=marked BP elevation + presence of acute symptoms or progressive target organ damage
    • Brain (Stroke, ICH, encephalopathy)
    • Eyes (hypertensive retinopathy)
    • Heart (MI, CHF, Dissection)
    • Kidneys (hematuria, AKI)

Causes of secondary hypertension:

2ndary HTN

Pheochromocytoma:

  • Risk factors: family history, genetic syndromes (Von Hippel-Lindau disease, MENIIa or IIb, Neurofibromatosis-I)
  • Clinical features: “triad” of headache, palpitations, diaphoresis seen only a fraction of the time
  • Triggers of episodes: anesthesia, drugs (contrast, glucagon, metoclopramide, TCA, foods/beverages)
  • When to consider testing for possible pheochromocytoma:
    • Clinical triad
    • Hyperadrenergic spells (episodic palpitations diaphoresis, headache tremor, pallor)
    • Early onset HTN, resistant HTN, or HTN with new onset DM2 in slender patient
    • Familial syndrome (VHL, MEN, NF1)
    • Adrenal incidentaloma + HTN
    • Paroxysmal HTN with anesthesia/surgery
    • Family History of pheochromocytoma
    • History of gastric stromal tumor or pulmonary chondroma
  • Biochemical Testing:
    • Caveat: levels altered by certain drugs and diseases so must take clinical context into consideration and stop drugs, if able
      • Drugs: TCAs, psychotropics, prochlorperazine, decongestants, levodopa
    • 24 hour urinary fractionated metanephrines & catecholamines
    • plasma fractionated metanephrines
    • Note:
      • Metanephrines: metanephrine and normetanephrine
      • Catecholamines: Norepinephrine, epinephrine, and dopamineflowchart
  • Imaging:
    • Proceed with imaging if biochemical analysis positive
    • CT or MRI
    • If CT or MRI negative (but biochemical positive), possibilities include:
      • Wrong diagnosis (false positive biochemistry)
      • Extra-adrenal mass (i.e. paraganglioma)
        • Evaluate with MIBG scan
        • Other indications for MIBG: very large adrenal mass (higher malignant/metastatic risk)
  • Genetic Testing:
    • indicated if:
      • unilateral pheochromocytoma, age <45 years
      • Associated genetic syndrome
      • Extra-adrenal paraganglioma
      • Bilateral pheochromocytoma
      • Unilateral pheochromocytoma with family history
  • Management considerations:
    • surgical adrenalectomy (laparoscopic preferred)
    • Preparation for surgery:
      • Start alpha blockade first (phenoxybenzamine or alpha 1 antaongists like doxazosin/terazosin)
        • Then start high salt intake (i.e. 5 g/day)-reverse catecholamine-related volume contraction/prevent CV collapse post-resection
      • Start beta blockade once adequate alpha blockade achieved
        • start low, go slow (risk of CHF due to catecholamine-related cardiomyopathy)
      • Patient to measure home BP BID; target <120/80 seated and sBP>90 standing
    • Perioperative considerations:
      • Hemodynamic monitoring
      • Acute HTN-IV infusion of nitro good option
      • Post-op HoTN: IV fluids
      • Post-op hypoglycemia: IV dextrose-containing solution

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