Summary

We report two cases of patients who were hospitalised for hypertensive emergency. In both cases, laboratory testing during admission revealed elevated normetanephrines in the range of 4–5 times the upper limit of normal using liquid chromatography with mass spectrometry. Imaging studies did not localise any phaeochromocytoma or paraganglioma (PPGL). Repeat biochemical testing after discharge was within normal limits in both cases. These observations suggest that hypertensive emergency should be recognised as a potential cause of ‘false-positive’ laboratory findings in the diagnostic assessment for PPGL.