Neuro-oncology is the study of brain and spinal cord neoplasms, many of which are (at least eventually) very dangerous and life-threatening (astrocytoma, glioma, glioblastoma multiforme, ependymoma, pontine glioma, and brain stem tumors are among the many examples of these). Among the malignant brain cancers, gliomas of the brainstem and pons, glioblastoma multiforme, and high-grade (highly anaplastic) astrocytoma are among the worst. [Source: Wikipedia ]