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HelpTest Code META3 Metanephrines with 3-Methoxytyramine, 24 Hour, Urine
Reporting Name
Metanephrines with 3-MT, 24h, UPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Useful For
A first- and second-tier screening test for the presumptive diagnosis of catecholamine-secreting pheochromocytomas and paragangliomas
Method Name
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Ordering Guidance
Necessary Information
24-Hour volume (in milliliters) is required.
Specimen Required
Patient Preparation: Tricyclic antidepressants, labetalol, and sotalol medications may elevate levels of metanephrines producing results that cannot be interpreted. If clinically feasible, it is optimal to discontinue these medications at least 1 week before collection. For advice on assessing the risk of removing patients from these medications and alternatives, consider consultation with a specialist in endocrinology or hypertension.
Supplies: Urine Tubes, 10 mL (T068)
Submission Container/Tube: Plastic urine tube
Specimen Volume: 10 mL
Collection Instructions:
1. Complete 24-hour urine collections are preferred, especially for patients with episodic hypertension; ideally the collection should begin at the onset of a "spell."
2. Add 10 g (pediatric: 3 g) of boric acid or 25 mL (pediatric: 15 mL) of 50% acetic acid as preservative at start of collection.
3. Collect urine for 24 hours.
Specimen Type
UrineSpecimen Minimum Volume
4 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 28 days | |
| Frozen | 28 days | ||
| Ambient | 21 days |
Reject Due To
| Gross hemolysis | OK |
| Gross icterus | OK |
Reference Values
3-Methoxytyramine:
Males: ≤306 mcg/24 h
Females: ≤242 mcg/24 h
METANEPHRINE
Males
Normotensives
3-8 years: 29-92 mcg/24 h
9-12 years: 59-188 mcg/24 h
13-17 years: 69-221 mcg/24 h
≥18 years: 44-261 mcg/24 h
Reference values have not been established for patients that are younger than 36 months.
Hypertensives: <400 mcg/24 h
Females
Normotensives
3-8 years: 18-144 mcg/24 h
9-12 years: 43-122 mcg/24 h
13-17 years: 33-185 mcg/24 h
≥18 years: 30-180 mcg/24 h
Reference values have not been established for patients that are younger than 36 months.
Hypertensives: <400 mcg/24 h
NORMETANEPHRINE
Males
Normotensives
3-8 years: 34-169 mcg/24 h
9-12 years: 84-422 mcg/24 h
13-17 years: 91-456 mcg/24 h
18-29 years: 103-390 mcg/24 h
30-39 years: 111-419 mcg/24 h
40-49 years: 119-451 mcg/24 h
50-59 years: 128-484 mcg/24 h
60-69 years: 138-521 mcg/24 h
≥70 years: 148-560 mcg/24 h
Reference values have not been established for patients that are younger than 36 months.
Hypertensives: <900 mcg/24 h
Females
Normotensives
3-8 years: 29-145 mcg/24 h
9-12 years: 55-277 mcg/24 h
13-17 years: 57-286 mcg/24 h
18-29 years: 103-390 mcg/24 h
30-39 years: 111-419 mcg/24 h
40-49 years: 119-451 mcg/24 h
50-59 years: 128-484 mcg/24 h
60-69 years: 138-521 mcg/24 h
≥70 years: 148-560 mcg/24 h
Reference values have not been established for patients that are younger than 36 months.
Hypertensives: <900 mcg/24 h
TOTAL METANEPHRINE
Males
Normotensives
3-8 years: 47-223 mcg/24 h
9-12 years: 201-528 mcg/24 h
13-17 years: 120-603 mcg/24 h
18-29 years: 190-583 mcg/24 h
30-39 years: 200-614 mcg/24 h
40-49 years: 211-646 mcg/24 h
50-59 years: 222-680 mcg/24 h
60-69 years: 233-716 mcg/24 h
≥70 years: 246-753 mcg/24 h
Reference values have not been established for patients that are younger than 36 months.
Hypertensives: <1300 mcg/24 h
Females
Normotensives
3-8 years: 57-210 mcg/24 h
9-12 years: 107-394 mcg/24 h
13-17 years: 113-414 mcg/24 h
18-29 years: 142-510 mcg/24 h
30-39 years: 149-535 mcg/24 h
40-49 years: 156-561 mcg/24 h
50-59 years: 164-555 mcg/24 h
60-69 years: 171-616 mcg/24 h
≥70 years: 180-646 mcg/24 h
Reference values have not been established for patients that are younger than 36 months.
Hypertensives: <1300 mcg/24 h
For International System of Units (SI) conversion for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html
Interpretation
Further clinical investigation (eg, radiographic studies) and genetic studies might be warranted in patients whose 3-methoxytyramine (3MT), metanephrine, or normetanephrine are elevated or when there is a very high clinical index of suspicion.
Increased 3MT levels are found in patients with pheochromocytoma and dopamine-secreting tumors.
3MT levels of 306 mcg/24 h or less in male patients and 242 mcg/24 h or less in female patients can be detected in non-pheochromocytoma hypertensive patients.
Day(s) Performed
Monday through Friday
Report Available
3 to 5 daysTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
82542
83835
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| META3 | Metanephrines with 3-MT, 24h, U | 101400-0 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 8552 | Metanephrine, U | 104629-1 |
| 609422 | 3-Methoxytyramine, U | 32618-1 |
| 21545 | Normetanephrine, U | 104631-7 |
| 83006 | Total Metanephrines, U | 104630-9 |
| TM50 | Collection Duration (h) | 13362-9 |
| VL48 | Volume (mL) | 3167-4 |
| 2434 | Comment | 48767-8 |
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| 3MT1 | 3-Methoxytyramine, U | Yes, (Order 3MT) | Yes |
| METAF | Metanephrines, Fractionated, 24h, U | Yes | Yes |