Urinary catecholamines and the diagnosis of phaeochromocytoma in Auckland

To review the experience in Auckland with the use of urinary catecholamine measurements in the diagnosis of phaeochromocytoma.

Review of the test results of patients with proven phaeochromocytoma and retrospective analysis of the outcome of patients with increased 24-hour urinary excretion of the catecholamines noradrenaline, adrenaline and dopamine.

Over six years the majority (16/18) of patients with proven phaeochromocytoma had raised urinary noradrenaline excretion either alone (3/16) or with raised adrenaline and/or dopamine (13/16). One phaeochromocytoma secreted adrenaline alone, none secreted dopamine alone and one had urinary catecholamine levels that were normal. Urinary adrenaline excretion was unexpectedly elevated in two patients with extra-adrenal phaeochromocytomas. Approximately 10% of 2590 24 hour urine specimens analysed over a 14 month period had an elevation of one or more catecholamine. Forty-six patients had urinary catecholamine excretion greater than twice the upper limit of normal. This group contained five of the six phaeochromocytomas diagnosed during this period. The other patients were normal (35/46, 76%) or were lost to follow up (6/46, 13%).

In this series most patients with phaeochromocytoma (89%) had increases in the 24-hour urinary excretion of one or more than one catecholamine which exceeded twice the upper limit of normal for our laboratory with noradrenaline being most commonly affected. Increased catecholamine excretion was often seen in patients without phaeochromocytoma.