This is a group of malignant tumours appearing in early childhood. They originate from cells of the primitive autonomic nervous system, although the majority come from the sympathetic part. 80% of those effective secrete abnormally large amounts of catecholamines, mainly adrenaline and noradrenaline. Between 50 and 80% are thought to arise in the adrenal medulla.
It affects between 8 and 10 million children under 15 years of age worldwide each year, and accounts for 10% of all childhood malignancies. It is the most frequent tumour occurring in the under 5 age group and half of all neonatal tumours are of this type.