Introduction of a testing service for the detection and monitoring phaeochromocytomas and paragangliomas (PPGLs)

Abstract

The clinical presentation of catecholamine-secreting tumor phaeochromocytomas and paragangliomas (PPGLs) is highly variable and if un-recognised, could be life threatening (Manger, 2009). Based on accumulated evidence from clinical research, Endocrine Society Clinical Practice Guidelines recommended the screening to include a biochemical test using blood sample [i.e. plasma free metanephrine (pfMETs)](Lenders et al., 2014). Of all available biochemical tests, pfMETs test with supine sampling provides the highest diagnostic value, with a sensitivity of 95% and a specificity of 95% for detecting PPGLs. However, the routine test we offer at East Kent is urinary catecholamine (uCATs), which requires a 24h urine sample and suffers from diagnostic sensitivity and specificity for detecting PPGLs. The pfMETs testing are currently only restricted for private requests and are sent away to a referral lab for analysis. In order to improve our service, we propose to introduce a new pfMETs test for the detection and monitoring PPGLs. This proposal will ensure East Kent stays in the forefront of diagnostic laboratory for screening PPGLs. The improved diagnostic sensitivity will reduce the risk of missing possible PPGLs. While the high diagnostic specificity will reduce unnecessary healthcare expenditure on subsequent follow-up investigations, such as expensive imaging and consultation costs. Furthermore, high specificity helps to avoid patient anxiety over false positive testing, time lost from work and hassle in traveling.

Outputs

From Wednesday 24 June 2020 our trust has introduced the plasma free metanephrines (pfMETs) to replace 24h urinary catecholamine (uCATs) for the investigation of phaeochromocytoma. Urine catecholamines (24h collection) will be completely withdrawn from our test repertoire on 31 August 2020. Introduction of this new service within the laboratories at EKHUFT is a real quality improvement, and a service development that I am very proud of.