=====Extracranial glioblastoma multiforme metastasis=====
Extracranial [[glioblastoma multiforme metastasis]] is extremely rare, but is being recognised in different imaging studies.

It occur most often in the lungs and pleura (60% of patients) but also in the regional lymph nodes (51%), bones (31%), and liver (22%)
((Slowik F, Balogh I (1980) Extracranial spreading of glioblastoma multiforme. Zentralbl Neurochir 41:57–68.))
((Pasquier B, Pasquier D, N'Golet A, et al. (1980) Extraneural metastases of astrocytomas and glioblastomas: Clinicopathological study of two cases and review of literature. Cancer 45:112–125.)).


 To date, the cause of the GBM metastatic spread still remains under discussion. It probably develops at the time of intracranial progression following a surgical procedure. According to other hypothesis, the metastases are a consequence of spontaneous tumour transdural extension or haematogenous dissemination 
((Grah JJ, Katalinic D, Stern-Padovan R, Paladino J, Santek F, Juretic A, Zarkovic K, Plestina S, Supe M. Leptomeningeal and intramedullary metastases of glioblastoma multiforme in a patient reoperated during adjuvant radiochemotherapy. World J Surg Oncol. 2013 Mar 5;11:55. doi:10.1186/1477-7819-11-55. PubMed PMID: 23496844; PubMed Central PMCID: PMC3599050.)).

===Spinal metastasis===

The ability of supratentorial GBM to metastasize along CSF pathways to the spinal cord was first described in 1931 ((Cairns H, Russell DS. Intracranial and spinal metastases in gliomas of the brain. Brain 1931;54:377-420.)).

A review of literature by Erlich et al. in 1978 revealed only 14 well documented cases of spinal subarachnoid seeding ((Erlich SS, Davis RL. Spinal subarachnoid metastasis from primary intracranial glioblastoma multiforme. Cancer 1978;42:2854-64.)).

After a stereotactic biopsy with stable intracranial disease, has only been reported in two cases. Traversing the lateral ventricle at the time of biopsy contributed to cerebrospinal fluid seeding with tumor cells and subsequent development of spinal disease ((Albert G, Wassef S, Dahdaleh N, Lindley T, Bruch L, Hitchon P. Intracranial glioblastoma with drop metastases to the spine after stereotactic biopsy. J
Neurol Surg A Cent Eur Neurosurg. 2013 Dec;74 Suppl 1:e221-4. doi:10.1055/s-0033-1345685. Epub 2013 Jun 26. PubMed PMID: 23804229.)).

Autopsy series suggest that approximately 25% of patients with intracranial glioblastoma have evidence of spinal subarachnoid seeding, although the exact incidence is not known because postmortem examination of the spine is not routinely performed 
((Erlich SS, Davis RL. Spinal subarachnoid metastasis from primary intracranial glioblastoma multiforme. Cancer 1978;42:2854-64.))
((Lam CH, Cosgrove GR, Drislane FW, Sotrel A. Spinal leptomeningeal metastasis from cerebral glioblastoma. Appearance on magnetic resonance imaging. Surg Neurol 1991;35:377-80.)).

The incidence is higher (of up to 60%) for infratentorial GBM ((Salazar OM, Rubin P. The spread of glioblastoma multiforme as a determining factor in the radiation treated volume. Int J Radiat Oncol Biol Phys 1976;1:627-37.)).

Although the spread of supratentorial glioblastoma multiforme to the brain stem and spine has been extensively described in published autopsy series, information on the diagnosis, treatment, and subsequent clinical course of patients manifesting symptoms of glioblastomatous dissemination ante mortem remains scant. 

They may spread along compact fiber pathways such as corpus callosum, optic irradiation, anterior commisure, and fornix or via cerebrospinal fluid (CSF) pathways. However, when GBM is under apparent control, spinal metastases are clinically rarely detected. Although involvement of the spinal cord (SC) has been noted with increasing frequency in recent years, literature provides only a few well documented cases ((Birbilis TA, Matis GK, Eleftheriadis SG, Theodoropoulou EN, Sivridis E. Spinal
metastasis of glioblastoma multiforme: an uncommon suspect? Spine (Phila Pa
1976). 2010 Apr 1;35(7):E264-9. doi: 10.1097/BRS.0b013e3181c11748. PubMed PMID:
20195200.)).

The number of cases of spinal metastasis from primary intracranial GBM seems to be increasing. This might be due to improved diagnostic tools like CT and MRI, prolonged survival time due to improved therapy, or due to changes in the biological properties of tumors as a result of surgery, radiotherapy, and chemotherapy.

In 11 patients having the signs and symptoms of neuraxis dissemination of supratentorial glioblastoma multiforme. All patients had radiographic documentation of metastases by either contrast-enhanced myelograms or enhanced magnetic resonance imaging scans. Ten presented with spinal involvement, whereas one presented with lower cranial neuropathies secondary to diffuse involvement of the basal cisterns. The mean age of the patients was 38.5 years, and the mean time interval between diagnosis of intracranial disease and diagnosis of metastases was 14.1 months. After diagnosis of tumor spread, subsequent mean survival time was 2.8 months. All patients received additional radiotherapy to the areas of metastasis, but the clinical response to radiotherapy was quite poor. This study confirms previous reports in the literature suggesting that metastases occur in younger patients and in patients with extended survival. The findings suggest that the relatively infrequent clinical incidence of the symptomatic spread of glioblastoma multiforme, as compared with the frequent incidental discovery of such spread at autopsy, may be the result of the limited survival of the affected patients, and not due to the biology of the tumor ((Vertosick FT Jr, Selker RG. Brain stem and spinal metastases of supratentorial
glioblastoma multiforme: a clinical series. Neurosurgery. 1990 Oct;27(4):516-21; 
discussion 521-2. PubMed PMID: 2172859.)).

===Spinal leptomeningeal metastasis (SLM)=== 
see [[spinal leptomeningeal metastasis]]

===Intramedullary===
Intramedullary spinal metastases are still rarer with only six cases reported till 2008 ((Scoccianti S, Detti B, Meattini I, Iannalfi A, Sardaro A, Leonulli BG,Martinelli F, Bordi L, Pellicanò G, Biti G. Symptomatic leptomeningeal and intramedullary metastases from intracranial glioblastoma multiforme: a case report. Tumori. 2008 Nov-Dec;94(6):877-81. PubMed PMID: 19267111.)).
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====Case reports====
A young patient with multiple visceral and osseous metastases occurred after 4 years after first diagnosis of GBM. The strangeness as well as the rarity of this event does not allow to identify an effective treatment for GBM metastases, making the management of this ominous tumor an even greater challenge
((Simonetti G, Silvani A, Fariselli L, Hottinger AF, Pesce GA, Prada F, Gaviani 
P. Extra central nervous system metastases from glioblastoma: a new possible
trigger event? Neurol Sci. 2017 Jun 24. doi: 10.1007/s10072-017-3036-0. [Epub
ahead of print] PubMed PMID: 28647829.
)).