pediatrics
Overview of Central Nervous System Tumors in Children
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 usedclassification 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. 