Tumors in the central nervous system (CNS) occur:
- intracranially (the brain)
- intraspinally (spinal cord, under 10%)
Brain tumors are the most frequently occurring solid tumors among children. About 40 new cases are diagnosed annually in children below 15 years in Norway. Astrocytomas constitute the largest group of these tumors followed by medulloblastomas and ependymomas.
Tumor localizations are different in children than adults. In children, almost half of the tumors are localized in the posterior cranial fossa despite only 15% of the tissue mass in the central nervous system being located there.
When treating intracranial tumors in children, one must be aware that the pediatric brain is not fully developed. Tolerance for surgery in children is good. Side effects of chemotherapy, and especially conventional radiation therapy, are severe.
In 2012, there were 35 children (0-14 years) diagnosed with tumors in the central nervous system in Norway. There were 22 boys and 13 girls (9). The incidence of children is 4/100,000.
Most of these are brain tumors. Brain tumors occur evenly distributed from the newborn period to the teenage years, and there is no significant drop in incidence during the childhood years as do many other pediatric tumors. Brain tumors are somewhat more frequent in boys than girls. A new study shows a ratio of 1.29 of males to females.