Urinary serotonin in the diagnosis of carcinoid tumors.
To determine whether measurement of serotonin in urine would give useful complementary information to the usual measurement of 5-hydroxyindoleacetic acid (5-HIAA) in urine and platelet serotonin in platelets, I measured these analytes in 75 consecutive patients with carcinoid tumors, and found that 75% had above-normal urinary 5-HIAA excretion, 64% had above-normal serotonin excretion, and 64% had above-normal platelet serotonin concentration. Six patients had increased urinary serotonin, but 5-HIAA excretion and platelet serotonin concentration were normal. Only two of a further 50 patients with solid noncarcinoid tumors--and none of 55 patients with flushing or diarrhea, who did not prove to have a carcinoid tumor--had increased urinary serotonin. Ingestion of four bananas (a food rich in serotonin) increased urinary 5-HIAA but not urinary serotonin excretion of seven normal subjects. Evidently, measurement of urinary serotonin excretion is helpful in the evaluation of patients with suspected carcinoid tumors.
Feldman
J M
JM
D000328:Adult; D000368:Aged; D001792:Blood Platelets / Q000032:analysis; D001984:Bronchial Neoplasms / Q000175:diagnosis* / Q000652:urine; D002276:Carcinoid Tumor / Q000175:diagnosis* / Q000652:urine; D005638:Fruit; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000652:urine; D008875:Middle Aged; D012701:Serotonin / Q000097:blood / Q000652:urine*
D012701:Serotonin; D006897:Hydroxyindoleacetic Acid