This rare tumor has a yearly occurrence of less than 5 per million children. Tumors of the nervous system vary in the degree of differentiation, which determines how they appear under the microscope and whether or not they are likely to spread. Benign tumors are less likely to spread. Malignant tumors are aggressive, grow quickly, and often spread. A ganglioneuroma is a benign tumor, while a neuroblastoma (occurring in children more than a year old) is generally malignant. A ganglioneuroblastoma may be localized to one area or widespread, but is usually less aggressive than a neuroblastoma. The cause is unknown.
| 
