Intracranial supratentorial tumors: classification, clinical findings, surgical management

Pediatric supratentorial tumors represent about 50% of all intracranial neoplasms. The most frequent tumors of the cerebral hemispheres are gliomas that arise from astrocytes, oligodendrocytes or ependymal cells. The incidence of the different histologic types is difficult to be established as many tumors have a mixed cellularity, thus classification is based on the prevalent oncotype or the most malignant component. Choroid plexus papillomas and ependymomas are the most common ventricular neoplasms. However, subependymal giant cell astrocytomas, subependymomas, teratomas are also observed. The parasellar region is a frequent site of pediatric tumors as craniopharyngiomas, optic pathway gliomas and germinomas. Pinealomas are less common. Signs and symptoms related to increased intracranial pressure are often reported and vary according to the patient's age. Macrocrania and a bulging fontanel can be observed in infants and toddlers, whereas headache, papilledema and vomiting are present in the older children. A tumor hindering CSF circulation may cause hydrocephalus. Focal signs include epilepsy and neurological deficits characteristic of tumor location. Total removal of the tumor is the ideal surgical therapy. When eloquent areas are involved, partial exeresis is indicated. Radiotherapy is usually administered to malignant tumors even if in younger children its use in markedly limited by the possible severe side-effects on the developing brain. Chemotherapy seems effective in some brain neoplasms, however most suitable drugs and dose need to be established. It may represent an alternative to radiotherapy in children less than three years of age.