Catecholamine secretion and ploidy in phaeochromocytoma

The aim was to evaluate 24 hr urine catecholamine, HMMA and HVA excretion i n relation to ploidy in phaeochromocytoma. Data from five diploid and nine tetraploid tumours showed a significant reduction in urine noradrenaline (p =0.02) and HMMA (p=0.03) in diploid tumours but no difference in adrenaline , dopamine and HVA excretion using the Mann-Whitney U test. None of the pat ients showed recurrence after a mean of 5.7 years of follow up. A review of published ploidy studies in phaeochromocytoma shows that malignancy is mor e than six times more common in non-diploid tumours but diploidy does not e quate with benignity. No biochemical marker is a reliable index of malignan cy, All patients should undergo lifetime review for recurrence.