Ganglioglioma
Updates to Article Attributes
Gangliogliomas are uncommon, usually low-grade, CNS tumours. Epilepsy is a common clinical presentation and this tumour has a typical occurrence in the temporal lobes, although they have been described in all parts of the central nervous system.
Their appearance on imaging is very variable: from a partially cystic mass with an enhancing mural nodule (~45% of cases) to a solid mass expanding the overlying gyrus. Contrast enhancement is variable.
Epidemiology
Children and young patients are usually affected, and no gender predominance is recognised. It accounts for around 2% (from 0.4-3.8%) of all primary intracranial tumours, and up to 10% of primary cerebral tumours in children.
Clinical presentation
The most common presentation is with temporal lobe epilepsy, presumably due to the temporal lobes being a favoured location.
Pathology
Gangliogliomas are WHO grade I tumours most frequently found in the temporal lobes (70%) 6,9 but do occur anywhere in the central nervous system.
In a minority of cases (5%) these tumours show aggressive behaviour and histopathologic features and are then called anaplastic gangliogliomas (WHO grade III) 7,9. At this stage, no criteria for WHO II gangliogliomas have been established 9.
Microscopic appearance
Gangliogliomas, as their name suggests, are composed of two cell populations:
- ganglion cells (large mature neuronal elements): ganglio-
- neoplastic glial element: -glioma
- primarily astrocytic, although oligodendroglial or pilocytic astroctytoma components are also enountered 9
The proportion of each component varies widely, and it is the grade of the glial component that determines biological behaviour.
Dedifferentiation into high-grade tumours does occasionally occur, and it is usually the glial component (into a GBM). Only rarely is it the neuronal component (into a neuroblastoma).
They are closely related to both gangliocytomas (which contain only the mature neural ganglion cellular component) and ganglioneurocytoma (which also have small mature neoplastic neurones).
Immunophenotype
Neuronal origin is demonstrated by positivity to neuronal markers 9:
- synaptophysin: positive
- neurofilament protein: positive
- MAP2: positive
- chromogranin-A: positive (usually negative in normal neurones) 9
- CD34: positive in 70-80%
The glial component may also show cytoplasmic positivity for GFAP.
Genetics
- BRAF V600E mutations are encountered in 20-60% of cases 9
- IDH: negative (if positive then the tumour is most likely a diffuse glioma) 9
Radiographic features
Imaging findings mirror the various patterns of growth which these tumours may demonstrate and thus their appearance is very variable. Partially cystic mass with an enhancing mural nodule is seen in ~45% of cases. They may also simply present as a solid mass expanding the overlying gyrus. An infiltrating mass is uncommon and may reflect higher grade.
CT
Findings are of a mass which is often non-specific. General features include:
- iso- or hypodense
- frequently calcified ~35%
- bony
remodelingremodelling or thinning can indicate the slow growing nature of the tumour - enhancement is seen in approximately 50% of cases (involving the solid non-calcified component)
MRI
Reported signal characteristics include:
-
T1
- solid component iso to hypointense
-
T1 C+ (Gd)
- solid component variable contrast enhancement
-
T2
- hyperintense solid component
- variable signal in the cystic component depending on the amount of proteinaceous material or presence of blood products
-
peritumoralperitumoural FLAIR/T2 oedema is distinctly uncommon
-
T2* (GE/SWI)
- calcified areas (common) will show blooming signal loss
Treatment and prognosis
Local resection is the treatment of choice and determines prognosis. In the brain, where a reasonable resection margin can be achieved, the prognosis is good, with recurrence-free survival reported to be 97% at 7.5-year follow-up 9.
In contrast, in the spinal cord where complete resection is often not possible without devastating deficits, local recurrence is very common.
If only incomplete resection is achievable, or tumour recurrence occurs then radiotherapy may be of some benefit.
Differential diagnosis
Main differential diagnosis is that of other cortical tumours, with helpful distinguishing features including 1-6:
-
dysembryoplastic neuroepithelial tumours (DNET)
- contrast enhancement uncommon
- 'bubbly appearance' common
-
pleomorphic xanthoastrocytoma (PXA)
- contrast enhancement prominent
- dural tail sign often seen
-
oligodendroglioma
- calcifications common
-
desmoplastic infantile astrocytoma and ganglioglioma
- young children
- dural involvement prominent
- large often multiple lesions
If in the spinal cord consider:
-<p><strong>Gangliogliomas</strong> are uncommon usually low-grade CNS tumours. Epilepsy is a common clinical presentation and this tumour has a typical occurrence in the temporal lobes, although they have been described in all parts of the central nervous system.</p><p>Their appearance on imaging is very variable: from a partially cystic mass with an enhancing mural nodule (~45% of cases) to a solid mass expanding the overlying gyrus. Contrast enhancement is variable.</p><h4>Epidemiology</h4><p>Children and young patients are usually affected, and no gender predominance is recognised. It accounts for around 2% (from 0.4-3.8%) of all primary intracranial tumours, and up to 10% of primary cerebral tumours in children.</p><h4>Clinical presentation</h4><p>The most common presentation is with <a href="/articles/temporal-lobe-epilepsy">temporal lobe epilepsy</a>, presumably due to the temporal lobes being a favoured location.</p><h4>Pathology</h4><p>Gangliogliomas are WHO grade I tumours most frequently found in the temporal lobes (70%) <sup>6,9</sup> but do occur anywhere in the central nervous system.</p><p>In a minority of cases (5%) these tumours show aggressive behaviour and histopathologic features and are then called <a href="/articles/anaplastic-ganglioglioma">anaplastic gangliogliomas</a> (WHO grade III) <sup>7,9</sup>. At this stage, no criteria for WHO II gangliogliomas have been established <sup>9</sup>. </p><h5>Microscopic appearance</h5><p>Gangliogliomas, as their name suggests, are composed of two cell populations:</p><ol>- +<p><strong>Gangliogliomas</strong> are uncommon, usually low-grade, CNS tumours. Epilepsy is a common clinical presentation and this tumour has a typical occurrence in the temporal lobes, although they have been described in all parts of the central nervous system.</p><p>Their appearance on imaging is very variable: from a partially cystic mass with an enhancing mural nodule (~45% of cases) to a solid mass expanding the overlying gyrus. Contrast enhancement is variable.</p><h4>Epidemiology</h4><p>Children and young patients are usually affected, and no gender predominance is recognised. It accounts for around 2% (from 0.4-3.8%) of all primary intracranial tumours, and up to 10% of primary cerebral tumours in children.</p><h4>Clinical presentation</h4><p>The most common presentation is with <a href="/articles/temporal-lobe-epilepsy">temporal lobe epilepsy</a>, presumably due to the temporal lobes being a favoured location.</p><h4>Pathology</h4><p>Gangliogliomas are WHO grade I tumours most frequently found in the temporal lobes (70%) <sup>6,9</sup> but do occur anywhere in the central nervous system.</p><p>In a minority of cases (5%) these tumours show aggressive behaviour and histopathologic features and are then called <a href="/articles/anaplastic-ganglioglioma">anaplastic gangliogliomas</a> (WHO grade III) <sup>7,9</sup>. At this stage, no criteria for WHO II gangliogliomas have been established <sup>9</sup>. </p><h5>Microscopic appearance</h5><p>Gangliogliomas, as their name suggests, are composed of two cell populations:</p><ol>
-<a href="/articles/braf-1">BRAF</a> V600E mutations are encountered in 20-60% of cases <sup>9</sup>- +<em><a href="/articles/braf-1">BRAF</a></em> V600E mutations are encountered in 20-60% of cases <sup>9</sup>
-<a href="/articles/isocitrate-dehydrogenase">IDH</a>: negative (if positive then the tumour is most likely a diffuse glioma) <sup>9</sup>- +<em><a href="/articles/isocitrate-dehydrogenase">IDH</a></em>: negative (if positive then the tumour is most likely a diffuse glioma) <sup>9</sup>
-<li>bony remodeling or thinning can indicate the slow growing nature of the tumour</li>- +<li>bony remodelling or thinning can indicate the slow growing nature of the tumour</li>
-<li>peritumoral FLAIR/T2 oedema is distinctly uncommon</li>- +<li>peritumoural FLAIR/T2 oedema is distinctly uncommon</li>
Systems changed:
- Oncology
- Paediatrics
Unable to process the form. Check for errors and try again.