The clinical and laboratory correlates of an increased urinary 5-hydroxyindoleacetic acid. Issue 839 (September 1995)

• Record Type: Journal Article
• Authors: Tormey, W. P.; FitzGerald, R. J.
• Is Part Of: Postgraduate medical journal. Volume 71:Issue 839(1995)
• Page Start: 542
• Page End: 545
• Publication Date: 1995-09
• Subjects: Medicine -- Periodicals; 610
• DOI: 10.1136/pgmj.71.839.542
• Languages: English
• ISSNs: 0032-5473

Abstract

Abstract : Over a five-and-a-half-year period, there were 298 laboratory requests for urinary 5-hydroxyindoleacetic acid (5-HIAA). The clinical and laboratory associations of the 24 patients in which there were 43 urinary 5-HIAA 24-h collection results greater than the laboratory upper reference limit are detailed. Four were confirmed carcinoid tumours and two were phaeochromocytomas. Flushing was a prominent symptom in 46% and diarrhoea or altered bowel habit in 37%. Associated with the raised urinary 5-HIAA values were increased levels of 4-hydroxy-3-methoxymandelic acid and homovanillic acid in 14.3% and 21%, respectively, of those collections where the metabolites were requested. Diagnostic imaging was performed in 57%. While the specificity was 88%, 5-HIAA is relatively insensitive in the diagnosis of carcinoid tumours and a more widespread use of diagnostic imaging including isotope scanning with labelled metaiodo-benzylguanidine, vasoactive intestinal peptide and octreotide is suggested.