Diagnosis

Your doctor might order several tests.

Lab tests

The following tests measure levels of adrenaline, noradrenaline or byproducts of those hormones in your body:

• 24-hour urine test. In this test, you 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. Your doctor draws blood to be tested in the lab.

For both types of tests, talk with your doctor about special preparations, such as fasting or skipping a medication. Don't skip a medication dose without instructions from your doctor.

Imaging tests

If the lab test results suggest the presence of a pheochromocytoma or paraganglioma, your doctor will likely order one or more imaging tests to locate a possible tumor. These tests may include:

• CT scan, a specialized X-ray technology
• MRI, which 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 taken up by pheochromocytomas or paragangliomas
• Positron emission tomography (PET), a scanning technology that also can detect radioactive compounds taken up by a tumor

Imaging studies done for other reasons

A tumor in an adrenal gland might be found during imaging studies done for other reasons. In such cases, your doctor will generally order additional tests to determine the nature of the tumor.

Genetic testing

Your doctor might recommend genetic tests to determine whether a pheochromocytoma is related to an inherited disorder. Information about possible genetic factors can be important for many 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, your test results may affect treatment decisions or long-term plans to monitor your health.
• Results from your tests may suggest 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.