Catecholamines, Fractionated and VMA, 24‑Hour Urine without Creatinine
Use
Measurement of fractionated catecholamines (epinephrine, norepinephrine, dopamine) and vanillylmandelic acid (VMA) in a 24‑hour urine collection. This profile aids in diagnosis of catecholamine-secreting tumors such as pheochromocytomas and paragangliomas, and in evaluating neuroblastomas or related neuroendocrine disorders. Results should be interpreted in the context of clinical, family history, and physical findings.
Special Instructions
Collect a complete 24‑hour urine specimen using 25 mL of 6 N HCl preservative to maintain pH ≤ 3; if no preservative, refrigerated collection and frozen shipment are acceptable provided pH ≤ 6. Patients should preferably avoid medications for three days prior to collection (antihypertensives generally cause minimal interference). Prior to collection, patients should avoid alcohol, coffee, tea, tobacco (including patches), bananas, citrus fruits, and strenuous exercise.
Limitations
Intermittent or modestly secreted tumor activity may not elevate urinary catecholamine levels. Physiological stress or certain medications (e.g., acetaminophen, labetalol, sotalol) may cause false elevations. Completeness of 24‑hour urine collection may affect results—creatinine normalization (in alternate test versions) can help assess collection adequacy.
Methodology
Other
Biomarkers
Result Turnaround Time
Not provided.
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
Not provided
Minimum Volume
10 mL
Container
Plastic 24‑hour urine container
Collection Instructions
Collect 24‑hour urine; add 25 mL 6 N HCl preservative (pH ≤ 3). If no preservative, urine must have pH ≤ 6, be refrigerated during collection and shipped frozen.
Patient Preparation
Preferably off medications for three days (antihypertensives minimal interference). Avoid alcohol, coffee, tea, tobacco, bananas, citrus fruits, strenuous exercise prior to collection.
Storage Instructions
If unpreserved, refrigerate during collection and ship frozen.