At a Glance
Why Get Tested?
When to Get Tested?
When your child has an abdominal mass, bruising around the eyes, trouble walking, or bone pain; when you have symptoms of increased catecholamine release, such as persistent or episodic high blood pressure, severe headaches, rapid heart rate, and sweating; when you have been treated for a neuroendocrine tumor, such as neuroblastoma or pheochromocytoma
Test Preparation Needed?
This test is affected by caffeine, certain drugs, and stresses. Inform your doctor of any medications you are taking and follow any instructions you are given for things to avoid before sample collection.
The Test Sample
What is being tested?
Vanillylmandelic acid (VMA) is one of the metabolites of the catecholamines epinephrine (adrenaline) and norepinephrine. This test measures the amount of VMA that is excreted into the urine, typically over a 24-hour period, to detect excess catecholamine production.
Catecholamines are a group of similar hormones produced in the central portion of the adrenal glands, the adrenal medulla. Adrenal glands are small triangular organs located on top of each kidney. The primary catecholamines that they release are dopamine, epinephrine, and norepinephrine. These hormones are released into the bloodstream in response to physical or emotional stress. They help transmit nerve impulses in the brain, increase glucose and fatty acid release for energy, dilate bronchioles, and dilate the pupils. Norepinephrine also constricts blood vessels, increasing blood pressure, and epinephrine increases heart rate and metabolism. After completing their actions, the catecholamines are metabolized to inactive compounds. Dopamine becomes homovanillic acid (HVA), norepinephrine breaks down into normetanephrine and VMA, and epinephrine becomes metanephrine and VMA. Both the hormones and their metabolites are excreted in the urine.
VMA is usually present in the urine in small fluctuating amounts that only increase appreciably during and shortly after the body is exposed to a stressor. Neuroblastomas, pheochromocytomas, and other neuroendocrine tumors, however, can produce large amounts of catecholamines, resulting in greatly increased concentrations of the hormones and their metabolites. The hormone releases can cause persistent hypertension, severe headaches, palpitations, sweating, nausea, anxiety, and tingling in the extremities.
Neuroblastomas are rare cancers but, according to the American Cancer Society, they are the most common cancers affecting infants. About 700 new cases are diagnosed each year, primarily in babies one to two years old, with up to 90% of cases occurring in children under the age of five. Rarely, a baby may be born with a neuroblastoma. Arising from primitive nerve cells, the cancers can be found in the abdomen, adrenal glands, neck, chest, or pelvis. About two-thirds of the time, the tumors will have metastasized and moved to other parts of the body by the time they are diagnosed. Once detected, many neuroblastomas can be successfully treated. In some cases, neuroblastomas may disappear on their own or their cells may spontaneously mature into normal nerves cells, turning the neuroblastoma into a benign ganglioneuroma or into a partially benign ganglioneuroblastoma.
Pheochromocytomas are rare tumors that arise primarily in the adrenal glands. According to the National Cancer Institute, they affect 2 to 8 people per million per year, primarily those in their thirties to fifties. Most pheochromocytomas are benign and do not spread from their original location, but some may metastasize and move to other organs within the body. Left untreated, they continue to grow and produce catecholamines, and hormone-related symptoms continue to worsen. Over time, the hypertension that the pheochromocytoma causes may damage body organs, such as the kidneys and heart, and raise the risk of an affected person having a stroke or heart attack. Pheochromocytomas are important to diagnose because they represent a potentially curable form of hypertension. In most cases, they can be removed and/or treated to reduce or eliminate the associated symptoms and complications.
The VMA test, along with other tests for catecholamines and their metabolites, can be used to help detect the presence of neuroblastomas and pheochromocytomas.
How is the sample collected for testing?
For a 24-hour urine collection, all of the urine produced during a 24-hour period should be saved. It is important that the sample be refrigerated during this time period. A single urine sample is collected for a random urine test.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Is any test preparation needed to ensure the quality of the sample?
This test is affected by caffeine, certain drugs, and stresses. It is important to inform the health care provider of any medications being taken, including herbal supplements and over-the-counter products, and to follow any instructions provided for things to avoid before sample collection.
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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.
Sources Used in Current Review
Lin, J. (Updated 2012 March 16). Vanillylmandelic Acid (VMA). Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/2089620-overview through http://emedicine.medscape.com. Accessed June 2013.
Frank, E. (Updated 2013 May). Neuroblastoma. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/Neuroblastoma.html?client_ID=LTD#tabs=0 through http://www.arupconsult.com. Accessed June 2013.
Joyner, B. and Lopushnyan, N. (Updated 2012 October 10). Neuroblastoma. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/439263-overview through http://emedicine.medscape.com. Accessed June 2013.
Mayo Clinic staff (2011 April 5). Pheochromocytoma. Mayo Clinic [On-line information]. Available online at http://www.mayoclinic.com/print/pheochromocytoma/DS00569/DSECTION=all&METHOD=print through http://www.mayoclinic.com. Accessed June 2013.
Blake, M. and Sweeney, A. (Updated 2013 March 14). Pheochromocytoma. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/124059-overview through http://emedicine.medscape.com. Accessed June 2013.
Dugdale, D. (Updated 2011 June 1). Catecholamines – urine. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003613.htm through http://www.nlm.nih.gov. Accessed June 2013.
Pagana, K. D. & Pagana, T. J. (© 2011). Mosby's Diagnostic and Laboratory Test Reference 10th Edition: Mosby, Inc., Saint Louis, MO. Pp 1023-1026.
Sources Used in Previous Reviews
Pagana, K. D. & Pagana, T. J. (© 2007). Mosby's Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 987-990.
Wu, A. (© 2006). Tietz Clinical Guide to Laboratory Tests, 4th Edition: Saunders Elsevier, St. Louis, MO. Pp 1110-1113.
Dugdale, D. (Updated 2009 May 09). Catecholamines – urine. MedLinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003613.htm. Accessed August 2009.
(Modified 2008 February 08). Neuroblastoma Screening (PDQ®), Health Professional Version. National Cancer Institute [On-line information]. Available online at http://www.cancer.gov/cancertopics/pdq/screening/neuroblastoma/healthprofessional/allpages through http://www.cancer.gov. Accessed August 2009.
(Revised 2008 October 21). Detailed Guide: Neuroblastoma. American Cancer Society [On-line information]. Available online at http://www.cancer.org/docroot/CRI/CRI_2_3x.asp?rnav=cridg&dt=31 through http://www.cancer.org. Accessed August 2009.
Vuguin, P. (Updated 2009 August 27). Pheochromocytoma. eMedicine [On-line information]. Available online at http://emedicine.medscape.com/article/988683-overview through http://emedicine.medscape.com. Accessed September 2009.
Joyner, B. and Lopushnyan, N. (Updated 2007 December 4) Neuroblastoma eMedicine [On-line information]. Available online at http://emedicine.medscape.com/article/439263-overview through http://emedicine.medscape.com. Accessed September 2009.
(Updated 2009 August). Neuroblastoma. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/Neuroblastoma.html through http://www.arupconsult.com. Accessed September 2009.
Korones, D. (Revised 2009 January). Neuroblastoma: Merck Manual for Healthcare Professionals [On-line information]. Available online at http://www.merck.com/mmpe/sec19/ch285/ch285c.html?qt=VMA&alt=sh through http://www.merck.com. Accessed September 2009.
Grossman, A. (Revised 2007 November). Pheochromocytoma. Merck Manual for Healthcare Professionals [On-line information]. Available online at http://www.merck.com/mmpe/sec12/ch153/ch153h.html?qt=VMA&alt=sh through http://www.merck.com. Accessed September 2009.
Mayo Clinic Staff (2009 April 03). Pheochromocytoma. Mayoclinic.com [On-line information]. Available online at http://www.mayoclinic.com/print/pheochromocytoma/DS00569/DSECTION=all&METHOD=print through http://www.mayoclinic.com. Accessed September 2009.