Gliomatosis cerebri

Changed by Henry Knipe, 31 Aug 2015

Updates to Article Attributes

Body was changed:

Show markup changes

Gliomatosis cerebri is a rare, diffusely infiltrative ~~glial~~glial tumour that involves at least three lobes by definition⁵. There often is an important discordance between clinical and radiological findings, as it may be clinically silent while it appears as a very extensive process radiologically.

Epidemiology

~~Peak~~

peak incidence is at 20-40 years of age.
M:F of 1.5:1 in one sequential series of 54 patients ⁷

PatologyPathology

The tumour may be primary GC (de novo) ~~or secondary~~ or secondary, with the ~~last one as~~latter as a result from the spreading of a more focal glioma ⁵. Gliomatosis cerebri can contain areas of WHO grade 2 or 3 tumours, and rarely grade 4 ^6,7.

Classification

Gliomatosis cerebri can be divided into two types ⁷:

type 1: no discrete mass
type 2: discrete mass with further diffuse CNS involvement
- IDH1 mutation more common in this subtype ⁷

Radiographic features

CT

~~Can~~CT can be normal because lesions often isodense to normal brain parenchyma. There is relative lack of mass effect and distortion. There may be an ill ~~defined~~-defined asymmetry or subtle hypoattenuation to the involved brain parenchyma.

MRI

Mass effect and enhancement are minimal. There is loss of ~~GM/WM differenciation~~gray-white matter differentiation and diffuse gyral thickening.

Diffuse T1 and T2 prolongation throughout both white and grey matter.:

T1: iso to hypointense to grey matter ¹
T2: hyperintense to grey matter ¹
T1C+: typically no or minimal enhancement
DWI: usually no restriction
MR spectroscopy:
- elevated Cho:Crn and Cho:NAA ratios ²
- marked elevation of myoinositol (mI)
~~Perfusion~~perfusion MR:
- low ~~rCBV~~/normal rCBV: correlates with no vascular hyperplasia

PET

FDG PET shows marked hypometabolism

Treatment and prognosis

The condition carries a poor prognosis with an average survival of ≈ 50% at 1 year and 25% at 3 years. Transformation into ~~GBM~~glioblastoma~~/HAA may~~ may occur a few years later.

Surgery is not a suitable option due the diffuse nature of this tumour but can be used to treat complications such as hydrocephalus.

~~Radiotherapy is an option~~Radiation therapy has been shown to increase survival ⁷, however, the large field usually required in these lesions increases the risk of severe toxicity ⁵. Chemotherapy is a treatment option, although there is a lack evidence in its use (both positive and negative) ⁷.

Differential diagnosis

General imaging differential considerations include⁶:

progressive multifocal leukoencephalopathy (in immunocompromised patient): no mass effect
multicentric glioblastoma: may be indistinguishable
primary CNS lymphoma: usually vividly enhancing
encephalitis: different clinical presentation

-<p><strong>Gliomatosis cerebri</strong> is a diffusely infiltrative glial tumour that involves at least three lobes by definition <sup>5</sup>. There often is an important discordance between clinical and radiological findings, as it may be clinically silent while it appears as a very extensive process radiologically.</p><h4>Epidemiology</h4><p>Peak incidence is at 20-40 years of age.</p><h4>Patology</h4><p>The tumour may be primary GC (<em>de novo</em>) or secondary, the last one as a result from the spreading of a focal glioma <sup>5</sup>. </p><h4>Radiographic features</h4><h5>CT</h5><p>Can be normal because lesions often isodense to normal brain parenchyma. There is relative lack of mass effect and distortion. There may be an ill defined asymmetry or subtle hypoattenuation to the involved brain parenchyma.</p><h5>MRI</h5><p>Mass effect and enhancement are minimal. There is loss of GM/WM differenciation and diffuse gyral thickening.</p><p>Diffuse T1 and T2 prolongation throughout both white and grey matter.</p><ul>
+<p><strong>Gliomatosis cerebri</strong> is a rare, diffusely infiltrative <a href="/articles/cns-tumours-classification-and-grading-who">glial tumour</a> that involves at least three lobes by definition. There often is an important discordance between clinical and radiological findings, as it may be clinically silent while it appears as a very extensive process radiologically.</p><h4>Epidemiology</h4><ul>
+<li>peak incidence is 20-40 years of age</li>
+<li>M:F of 1.5:1 in one sequential series of 54 patients <sup>7</sup>
+</li>
+</ul><h4>Pathology</h4><p>The tumour may be primary (<em>de novo</em>) or secondary, with the latter as a result from the spreading of a more focal glioma <sup>5</sup>. Gliomatosis cerebri can contain areas of <a href="/articles/cns-tumours-classification-and-grading-who">WHO grade</a> 2 or 3 tumours, and rarely grade 4 <sup>6,7</sup>. </p><h5>Classification</h5><p>Gliomatosis cerebri can be divided into two types <sup>7</sup>:</p><ul>
+<li>type 1: no discrete mass</li>
+<li>type 2: discrete mass with further diffuse CNS involvement<ul><li>
+<a title="IDH1" href="/articles/isocitrate-dehydrogenase-1-idh1">IDH1 mutation</a> more common in this subtype <sup>7</sup>
+</li></ul>
+</li>
+</ul><h4>Radiographic features</h4><h5>CT</h5><p>CT can be normal because lesions often isodense to normal brain parenchyma. There is relative lack of mass effect and distortion. There may be an ill-defined asymmetry or subtle hypoattenuation to the involved brain parenchyma.</p><h5>MRI</h5><p>Mass effect and enhancement are minimal. There is loss of gray-white matter differentiation and diffuse gyral thickening.</p><p>Diffuse T1 and T2 prolongation throughout both white and grey matter:</p><ul>
~~-<strong>Perfusion MR:</strong><ul><li>low rCBV: correlates with no vascular hyperplasia</li></ul>~~
+<strong>perfusion MR:</strong><ul><li>low/normal rCBV: correlates with no vascular hyperplasia</li></ul>
-</ul><h5>PET</h5><ul><li>FDG PET shows marked hypometabolism</li></ul><h4>Treatment and prognosis</h4><p>The condition carries a poor prognosis with an average survival of ≈ 50% at 1 year and 25 % at 3 years. <a href="/articles/glioblastoma">GBM</a>/HAA may occur a few years later.</p><p>Surgery is not a suitable option due the diffuse nature of this tumour.</p><p>Radiotherapy is an option, however the large field usually required in these lesions increases the risk of severe toxicity <sup>5</sup>. </p><h4>Differential diagnosis</h4><p>General imaging differential considerations include:</p><ul>
+</ul><h5>PET</h5><ul><li>FDG PET shows marked hypometabolism</li></ul><h4>Treatment and prognosis</h4><p>The condition carries a poor prognosis with an average survival of ≈ 50% at 1 year and 25% at 3 years. Transformation into <a href="/articles/glioblastoma">glioblastoma</a> may occur a few years later.</p><p>Surgery is not a suitable option due the diffuse nature of this tumour but can be used to treat complications such as <a title="hydrocephalus" href="/articles/hydrocephalus">hydrocephalus</a>.</p><p>Radiation therapy has been shown to increase survival <sup>7</sup>, however, the large field usually required in these lesions increases the risk of severe toxicity <sup>5</sup>. Chemotherapy is a treatment option, although there is a lack evidence in its use (both positive and negative) <sup>7</sup>.</p><h4>Differential diagnosis</h4><p>General imaging differential considerations include <sup>6</sup>:</p><ul>
~~-<li><p>multicentric <a href="/articles/glioblastoma">glioblastoma</a>: may be indistinguishable </p></li>~~
+<li>
+<a href="/articles/multicentric-glioblastoma">multicentric glioblastoma</a>: may be indistinguishable</li>
+<li>
+<a href="/articles/primary-cns-lymphoma">primary CNS lymphoma</a>: usually vividly enhancing</li>
+<li>
+<a href="/articles/encephalitis">encephalitis</a>: different clinical presentation</li>

References changed:

6. Mauricio Castillo. Neuroradiology Companion. (2011) ISBN: 9781451111750 - <a href="http://books.google.com/books?vid=ISBN9781451111750">Google Books</a>
7. Chen S, Tanaka S, Giannini C et al. Gliomatosis Cerebri: Clinical Characteristics, Management, and Outcomes. J Neurooncol. 2013;112(2):267-75. <a href="https://doi.org/10.1007/s11060-013-1058-x">doi:10.1007/s11060-013-1058-x</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/23341100">Pubmed</a>

Images Changes: