Background: This protocol is designed to evaluate patients with tumors of the central nervous system (CNS) who appear to be probable candidates for future protocol entry or have disease manifestations that are of unique scientific interest, importance, and/or educational value. Objectives: 1) To evaluate patients with tumors of the central nervous system (CNS) who are probable future candidates for NCI Phase I and II protocols. 2) To follow patients with tumors of the CNS that are representative of important scientific and/or clinical principles. 3) To allow a steady flow of patients with tumors of the CNS at the NIH for the purpose of educating nurses, medical students, residents, clinical fellows, and physicians in the management and care of this specialized subgroup of cancer patients. Eligibility: 1) All patients 12 months of age with tumors of the CNS of interest to the NOB, who may be candidates for another NOB trial at some point in the future. 2) Patients with tumors of the CNS that are of particular interest to members of the NOB because they pose important clinical and/or scientific questions and/or shed light on important aspects of the disease. 3) Patients with tumors of the CNS who offer an important educational benefit to neuro-oncology trainees and staff. 4) Ability of subject or Legally Authorized Representative (LAR) to understand and the willingness to sign a written informed consent document. Availability of a parent or legal guardian to give informed consent for children. Design: 1) All patients will undergo an initial evaluation at the Clinical Center by a member of the NOB where past medical and oncologic histories will be obtained as well as relevant data such as neuroimaging and pathology review. A total of 3,000 patients will be accrued to this study. 2) Patients may be seen at the NIH Clinical Center at varying intervals depending on the clinical situation but data related to the natural history of their disease course and outcome will be collected at least every six months.