- Patients must have histologically confirmed initial diagnosis of primary intracranial World Health Organization (WHO) Grade IV malignant glioma (glioblastoma, GBM), now recurrent. Patients with recurrent disease whose initial diagnostic pathology confirmed glioblastoma will not need re-biopsy. Alternately, patients with prior intracranial low-grade glioma or anaplastic glioma will be eligible, if histologic assessment demonstrates transformation to GBM (first diagnosis of secondary GBM).