Shin T, Hoang TD, Plunkett MT, Shakir MKM. False elevations in urinary metanephrines: under-recognised pitfall with 24-hour urinary volume collection.
BMJ Case Rep 2021;
14:e241147. [PMID:
33541972 PMCID:
PMC7868217 DOI:
10.1136/bcr-2020-241147]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2021] [Indexed: 11/30/2022] Open
Abstract
One pitfall in 24-hour urine collection is the input of incorrect urinary volume by the reference laboratory. This may lead to an incorrect diagnosis of pheochromocytoma or paraganglioma. A 48-year-old African-American woman was seen in the clinic for an elevated 24-hour urine metanephrine screen during workup for secondary hypertension. Urine volume was found to be incorrectly inputted by the lab as 9750 mL rather than 975 mL. The urinary metanephrines were then recalculated and the 24-hour urinary metanephrines resulted within normal limits. This case highlights this unique and potentially under-recognised error in testing with 24-hour urine volume collection.
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