5-HIAA (5-Hydroxyindolacetic Acid)

Sample: Urine 24 hrs in 6N HCl. (Avoid diet with bananas, vanilla, chocolates, tomatoes).

Schedule: One Week (HPLC UV/VIS)

Units: mg/24 hrs

Range: Up to 10 mg/24 hrs


5-HIAA (5-Hydroxyindolacetic acic) is a metabolite of Serotonin and is produced in the presence of carcinoid tumors. 5-HIAA may be normal in patients with non-metastasic carinoid tumor. The concentration of 5-hydroxyindolacetic acid (5-HIAA) in urine is a diagnostic marker for the carcinoid syndrome. This malignant proliferation of the enterochromaffin cells of the gastrointestinal tract leads to an excessive production of the tissue hormone serotonin, the major metabolite of which is 5-HIAA.The best procedure for the measurement of 5-HIAA is the HPLC technique:

HPLC Chromatogram for 5-HIAA


Available tests