A single institution experience of the incidence of extracranial metastasis in glioma.

Glioblastoma multiforme (GBM) is the most common and aggressive subtype of all gliomas. The prognosis is poor but despite the aggressiveness of the tumour, extracranial metastasis of glioma is rare. Most documented cases of extracranial metastases of GBM involve leptomeningeal spread to the spine. In this clinical study we aim to review the incidence and location of extracranial metastasis of glioma from the Brain Tumor Database of the National Neuroscience Institute of Singapore, between September 2004 to October 2009. Four of 148 patients (2.7%) were identified, one of whom had pleomorphic xanthoastrocytoma (PXA) with scalp and spinal metastasis, suggestive of haematogenous rather than cerebrospinal fluid spread that has been described elsewhere. To our knowledge, there has been no published report of PXA with scalp metastasis or vertebral metastasis.