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, 24 Hour, Urine), and serum chromogranin A (CGAK / Chromogranin A, Serum).

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 discontinue medications that may elevate urine serotonin concentration including lithium, monoamine oxidase inhibitors, methyldopa, morphine, and reserpine. Patient should discontinue use of selective serotonin reuptake inhibitors (SSRI eg, PROZAC), which can lead to depletion of platelet serotonin levels and result in false-negative serotonin results.

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 2.5 mL

Collection Instructions: Centrifuge as soon as blood has clotted and aliquot serum into plastic vial.