(Science: oncology, tumour) malignant tumour derived from primitive ganglion cells. Mainly a tumour of childhood. Commonest sites are adrenal medulla and retroperitoneal tissue. The cells may partially differentiate into cells having the appearance of immature neurons.
The tumour shows a consistent deletion of the 1p36 region which is considered the site of the neuroblastoma I gene. Loss of the 1p36 region also correlates with amplification for the N-myc oncogene, particularly in later stages of the disease.