Central nervous system (CNS) tumors are the leading cause of cancer mortality in children, accounting for 30% of deaths (1 Reference Central nervous system tumors are the most common solid cancer in children < 15 years old and are the leading cause of childhood death due to cancer. Diagnosis is typically by imaging (usually... read more ). The cause of most childhood central nervous system tumors is unknown, but two established risk factors are ionizing radiation (eg, high-dose cranial irradiation) and specific genetic syndromes (eg, neurofibromatosis Neurofibromatosis Neurofibromatosis refers to several related disorders that have overlapping clinical manifestations but that are now understood to have distinct genetic causes. It causes various types of benign... read more 
).
The most common central nervous system tumors in children are (in order)
Reference
1. Curtin SC, Minino AM, Anderson RN: Declines in cancer death rates among children and adolescents in the United States, 1999–2014. NCHS Data Brief (257):1–8, 2016.
Symptoms and Signs of CNS Tumors in Children
Increased intracranial pressure is the cause of the most common manifestations, which include
Headache
Nausea and vomiting
Irritability
Lethargy
Changes in behavior
Gait and balance disorders
Other common symptoms are related to tumor location, including vision loss and seizures.
Diagnosis of CNS Tumors in Children
MRI
Biopsy
MRI is the imaging test of choice because it provides more detailed images of parenchymal tumors and can detect tumors within the posterior fossa, subarachnoid spaces, and the arachnoid and pia mater. CT may be done but is less sensitive and less specific.
Once imaging confirms the presence of a brain tumor, a biopsy is needed in a majority of cases to confirm the diagnosis and to determine tumor type and grade. The World Health Organization (WHO) has created a commonly used classification system (2021) that includes molecular and histologic information to further classify central nervous system tumors.
Once a diagnosis is made and tumor histology is determined, staging and risk assessment are then determined. Staging (determination of whether the tumor has spread) includes an MRI of the entire spine, a lumbar puncture for cerebrospinal fluid cytology, and a postoperative MRI to assess for any residual tumor. Risk assessment is based on age, degree of residual tumor, molecular findings, and evidence of spread of disease.
Treatment of CNS Tumors in Children
Surgical resection
Radiation therapy, chemotherapy, or a combination
Treatment approach depends on the diagnosis, grade, stage, and risk assessment. In general, after initial surgery, radiation therapy, chemotherapy, or both may be required.
Entry into a clinical trial, if available, should be considered for all children with a CNS tumor. Optimal treatment requires a multidisciplinary team of pediatric oncologists, pediatric neuro-oncologists, pediatric neurosurgeons, neuropathologists, neuroradiologists, and radiation oncologists who have experience treating CNS tumors in children. Because radiation therapy for CNS tumors is technically demanding, children should be sent to centers that have experience in this area if possible.
More Information
The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
World Health Organization (WHO): WHO Grading of Tumours of the Central Nervous System (2021)
