[Brain tumors: classification and clinical aspects].

Brain tumors represent 40% to 50% of all solid tumors in children under 18 years of age, with an average incidence of 2 to 5 cases per 100,000/annum. These tumors are gliomas in 60% to 70% of cases. The most common location is infratentorial (60% of cases), with cerebellar astrocytomas, medulloblastomas and brain stem gliomas occurring in equal measure (20%). Astrocytomas are the predominant form (25%) in the supratentorial compartment. This review analyses clinical symptoms and instrumental procedures for the diagnosis of various types of brain tumor, together with recommendations for their management based on controlled clinical trials.