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Test Code SERU Serotonin, 24 Hour, Urine

Reporting Name

Serotonin, 24 Hr, U

Useful For

The diagnosis of a small subgroup of carcinoid tumors that produce predominately 5-hydroxytryptophan (5-HTP), but very little serotonin and chromogranin A

 

Follow-up of patients with known or treated carcinoid tumors that produce predominately 5-HTP, but very little serotonin and chromogranin A

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Urine


Additional Testing Requirements


First-line testing for the diagnosis of carcinoid tumors with symptoms suggestive of carcinoid syndrome consists of urinary serotonin (SERU / Serotonin, 24 Hour, Urine), urinary 5-HIAA (HIAA / 5-Hydroxyindoleacetic Acid [5-HIAA], 24 Hour, Urine), and serum chromogranin A (CGAK / Chromogranin A, Serum).



Necessary Information


24-Hour volume is required.



Specimen Required


Patient Preparation:

1. Patients should not eat avocados, bananas, butternuts, cantaloupe, dates, eggplant, grapefruit, hickory nuts, honeydew melon, kiwifruit, melon, nuts, pecans, pineapple, plantains, plums, tomatoes, or walnuts, which are high in serotonin for 48 hours before and during collection.

2. Patient should be off of medications that may elevate urine serotonin concentration including lithium, monoamine oxidase-inhibitors, methyldopa, morphine, and reserpine. Patient should also be off of selective serotonin reuptake inhibitors (eg, PROZAC) that can lead to depletion of platelet serotonin levels and result in false-negative urine serotonin tests.

3. Patient should avoid heavy nicotine consumption during the 24-hr collection period.

Container/Tube: Plastic, 10-mL urine tube (T068)

Specimen Volume: 5 mL

Collection Instructions:

1.  Add 25 mL of 50% acetic acid as preservative at start of collection.

2. Collect urine for 24-hours.

3. Refrigerate specimen during collection.

Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens in Special Instructions for multiple collections.


Specimen Minimum Volume

2.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 28 days
  Frozen  28 days
  Ambient  48 hours

Reference Values

≤210 mcg/24 hours 

Reference values apply to all ages.

Day(s) and Time(s) Performed

Monday, Wednesday, Friday; 10 a.m.

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

84260

LOINC Code Information

Test ID Test Order Name Order LOINC Value
SERU Serotonin, 24 Hr, U 18253-5

 

Result ID Test Result Name Result LOINC Value
26603 Serotonin, 24 Hr, U 18253-5
TM80 Collection Duration 13362-9
VL67 Urine Volume 3167-4

Reject Due To

Gross hemolysis OK

Method Name

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Urine Preservative Collection Options

Ambient

Yes

Refrigerate

Preferred

Frozen

Yes

50% Acetic Acid

Preferred

Boric Acid

No

Diazolidinyl Urea

No

6M Hydrochloric Acid

No

6M Nitric Acid

Yes

Sodium Carbonate

No

Thymol

No

Toluene

Yes