Background: A range of laboratory tests are available for investigation of phaeochromocytoma/paraganglioma (PPGL) and there is scope for significant variation in practice between centres. Endocrine Society Clinical Practice Guidelines make recommendations concerning the laboratory investigation of PPGL. We performed a national audit using these recommendations as audit standards.
Methodology: A questionnaire was distributed to all clinical biochemistry departments in the UK, who were encouraged to complete this with advice from endocrinology colleagues where required. The 21 questions included were designed to compare each centres practice to recommendations in the Endocrine Society guideline concerning the laboratory investigation of PPGL.
Results: 58 centres responded to the survey. Some of the key findings include: 95% of centres meet the recommendation that plasma or urine metanephrines (UMETs/PMETs) are included as part of first line testing. However, there are 12 different combinations of tests in use for biochemical testing indicating that different protocols are employed. All laboratories measuring metanephrines use either LCMS/MS or LC-ECD methods as recommended. There is significant variation in patient preparation before sampling for PMETs. For example, 28% of centres take PMETs samples only in seated patients, 14% supine only and 40% supine or seated in different situations (e.g. supine for borderline seated results). There are variations in the reference ranges used in different centres that could cause significant differences in interpretation (there is an up to twofold difference in the upper limits for UMETs for example).
Discussion: There is significant variation in the laboratory investigation of PPGL across different centres in the UK. The results of this audit highlight areas where practice may be improved and could inform further work on standardising the approach to investigating PPGL. Collaboration between the UK Endocrinology and Clinical Biochemistry communities will likely be required to address the findings of this audit.