5-HIAA (5-Hydroxyindoleacetic Acid), 24-Hour Urine with Creatinine : 1015172

Test Code
U5H24Q or 1015172

Alias/See Also
Carcinoid Screen; 5-HIAA; 5HIAA

CPT Codes
83497, 82570

Instructions
Patient should avoid food high in indoles: avocados, banana, tomato, plum, walnut, pineapple, and eggplant.

Collect 24-hour urine. Keep urine refrigerated during and after collection.

Transport Container
Transport 10 mL aliquot from a well-mixed 24-hour collection, (Min: 5 mL). Keep refrigerated. Record 24-hour total volume on transport container and test request form.

If transported to laboratory within 24 hours after collection, transport refrigerated.

If transport is delayed, see below alternate processing/transportation instructions:
A. After urine collection, add 6N HCl to maintain a pH below 3. Transport 10 mL aliquot of pH adjusted (less than pH 3) urine, refrigerated.
OR
B. If 6N HCL is not available, freeze 10 mL aliquot of urine and transport frozen.

Transport Temperature
Refrigerated.

Specimen Stability
Keep refrigerated during collection. Transport ASAP.

After preservation with 6 N HCL to pH 3: Ambient: 7 days; Refrigerated: 30 days; Frozen: 30 days

Methodology
High Performance Liquid Chromatography, Electrochemical Detection

Setup Schedule
Tuesday & Thursday & Friday

Report Available
3-7 days (From receipt at performing laboratory)

Limitations
Patients with renal disease may display falsely decreased results. Urinary 5-HIAA is increased in patients with malabsorption disorders who also display a larger concentration of urinary tryptophan metabolites. Urinary 5-HIAA is increased in patients with intestinal obstruction and with some noncarcinoid islet cell tumors. Carcinoid syndrome may not cause elevated results, especially if the patient does not have diarrhea. Requires accurate 24-hour urine collection.

Reference Range
2-10 yrs: less than or equal to 8.0 mg/24 h
>10 yrs: less than or equal to 6.0 mg/24 h

Clinical Significance
Values above 10 mg/24 hours occur in carcinoid syndrome. Slight elevations also occur in nontropical sprue and after reserpine administration. Drugs which can interfere with testing due to physiologic response: acetaminophen, alpha and beta blockers, atenolol, bromocriptine, broncholdilators, clonidine, digoxin, isoniazid, L-dopa, labetelol, methyldopa, monoamine oxidase inhibitors, nitroglycerin, sympathomimetic amines, phenobarbital, phenothiazines, phentolamine, reserpine, salicylates, tricyclic antidepressants.

Performing Laboratory
Quest Diagnostics



The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.