Glioblastoma multiforme in the adult conus medullaris.

De novo glioblastoma multiforme (GBM) of the spine is rare. We present a patient with a unique GBM arising within the conus and radiographically mimicking a filum terminale ependymoma. During surgery the lesion was notable for its highly vascular and diffuse infiltration of the surrounding spinal cord parenchyma. The operative goals were altered to account for the unexpected pathology. The treatment and prognosis of spinal GBM are briefly reviewed and the importance of considering an aggressive pathology when formulating a surgical plan for benign appearing lesions is emphasized.