Hypertension: biochemical tests could help rule out secondary causes.

Clinical bottom line (level 4)

  1. 6% of patients suspected of having a phaeochromocytoma had one.
  2. A negative test for plasma catecholamines, urinary VMA or metanephrines made a phaeochromocytoma less likely.
  3. A positive biochemical test made a phaeochromocytoma more likely but further tests are required.
Young et al: Journal of General Internal Medicine 1989; 4: 273-276
Expires Unknown Month 2002

The study

Setting: university hospital, USA

415 patients (aged ?, ?% male) suspected of having a phaeochromocytoma referred for a MIBG scan

Excluded if
  • previously known phaeochromocytoma
  • malignant phaeochromocytoma
  • suspicion of multiple endocrine neoplasia syndrome



    • Independent ?blinded reference standard, applied in all patients from a ?consecutive inappropriate spectrum.
    Reference standard:
    • histological evidence of chromaffin tissue. Patients were considered to have no disease if they had at least 1 negative test (MIBG, CT or ultrasound) and at least 1 year of follow-up with no diagnosis of phaeochromocytoma being made.
    Diagnostic test:
    • plasma total catecholamines (epinephrine plus norepinephrine: obtained after an overnight fast with patients recumbent for >1/2 hour with an indwelling venous catheter in place
    • urinary excretion of metanephrines over 12 hours overnight
    • urinary excretion of vanillylmandelic acid over 12 hours overnight

    The evidence

    pre-test probability of phaeochromocytoma: 6.3%, (95% CI: 3.9% to 8.6%)

    diagnostic test phaeochromocytoma no phaeochromocytoma LR+
    (95% CI)    		 post-test probability LR-
    (95% CI)    		 post-test probability
    plasma catecholamines > 950 pg/ml 20 23 13
    (8.3 to 20)     		47% 0.25
    (0.12 to 0.50)     		1.6%
    urinary metanephrines > 1.8 mg/24 hours 18 39 6.9
    (4.7 to 10)     		32% 0.34
    (0.19 to 0.61)     		2.2%
    urinary vanillylmandelic acid (VMA) > 11 mg/24 hours 20 19 16
    (9.7 to 26)     		51% 0.24
    (0.12 to 0.49)     		1.6%
    total 26 389

    Citation

    1. Young MJ, Dmuchowski C, Wallis JW, et al: Biochemical tests for pheochromocytoma: strategies in hypertensive patients. Journal of General Internal Medicine 1989; 4: 273-276
    Contributor: Chris Ball and Clare Wotton, Unknown Month 1999
    Reviewer:

    Clinical Question.
    Patient suspected phaeochromocytoma
    Intervention or Exposure biochemical tests
    Outcome diagnosis