Glioblastoma multiforme (GBM), also referred to as a Grade IV astrocytoma, is the most common type of primary brain tumor. It is a malignant tumor that carries a very poor prognosis, and typically results in death in 2 years. On CT and MRI imaging, the tumor is often large, irregular and infiltrative, and located in the white matter with surrounding edema. Histologically, the tumor is highly cellular and anaplastic with necrosis. Associated hemorrhage is not uncommon.

Clinically, patients present with slowly progressive focal neurological signs, and signs of increased intracranial pressure (i.e., headache, nausea, and vomiting). Seizures may be an initial presentation or may occur later in the course.