Tests and diagnosis

By Mayo Clinic Staff

Your doctor may order a number of tests.

Laboratory tests

Your doctor will likely order the following tests that measure levels of adrenaline, noradrenaline or byproducts of those hormones in your body:

  • 24-hour urine test. You will be asked to collect a urine sample every time you urinate during a 24-hour period. Ask for written instructions about how to store, label and return the samples.
  • Blood test. You will have blood drawn for laboratory work. Talk to your doctor about special preparations, such as fasting or skipping a medication. Do not skip a dose without specific instructions from your doctor.

Imaging tests

If the results of laboratory tests indicate the possibility of a pheochromocytoma or paraganglioma, your doctor will order one or more imaging tests to locate a possible tumor. These tests may include:

  • Computerized tomography (CT), a specialized X-ray technology
  • Magnetic resonance imaging (MRI), a technology that uses radio waves and a magnetic field to produce detailed images
  • M-iodobenzylguanidine (MIBG) imaging, a scanning technology that can detect tiny amounts of an injected radioactive compound that is taken up by certain tumors
  • Positron emission tomography (PET), a scanning technology that can also detect radioactive compounds taken up by a tumor

Incidental discovery

A tumor in an adrenal gland may be discovered incidentally during imaging studies conducted for other reasons. In such cases, your doctor would order additional tests to determine the nature of the tumor.

Genetic testing

Your doctor may recommend genetic tests to determine if a pheochromocytoma is related to an inherited disorder. Information about possible genetic factors can be important for a number of reasons:

  • Because some inherited disorders can cause multiple conditions, test results may indicate the need to screen for other medical problems.
  • Because some disorders are more likely to be recurrent or cancerous (malignant), your test results may affect treatment decisions or long-term plans to monitor your health.
  • Results from your tests may indicate that other family members should be screened for pheochromocytoma or related conditions.

Ask your doctor about genetic counseling services that can help you understand the benefits and implications of genetic testing.

May. 02, 2014

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