Insular Glioma Classification [Neurosurgery Wiki]

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====== Insular Glioma Classification ======

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[[Insular glioma]]s can be classified based on anatomical location, topographic extension, or involvement of subcortical white matter tracts. The following are the most referenced classification systems:
====== Insular Glioma Classifications ======

Insular gliomas are surgically complex due to their location near eloquent brain regions and deep vascular structures. Multiple classification systems help guide surgical planning and risk assessment.

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This page includes the **Berger–Sanai**, **Yaşargil**, **Mandonnet–Duffau**, and **Kawaguchi** classification systems.
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===== ▶ Berger–Sanai Classification (Most Used) =====

see [[Berger–Sanai Classification]]
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Divides the insula into four quadrants using:
  * **Horizontal axis** → Sylvian fissure  
  * **Vertical axis** → Foramen of Monro

  * **Zone I**: Anterior–superior  
  * **Zone II**: Posterior–superior  
  * **Zone III**: Posterior–inferior  
  * **Zone IV**: Anterior–inferior  

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✔ Simple and reproducible  
✔ Used in preoperative MRI  
✔ Zone II = ↑ risk (lenticulostriate arteries)
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===== ▶ Yaşargil Classification =====

[[Yasargil Classification of Insular Glioma]]
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Anatomical classification based on **topographic extension**.

  * **Type 3A**: Confined to insular cortex  
  * **Type 3B**: Involving perisylvian opercula  
  * **Type 5A**: Extends to paralimbic areas  
  * **Type 5B**: Includes hippocampus, frontal and temporopolar regions

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Used to understand **structural spread** beyond the insula.
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===== ▶ Mandonnet–Duffau Classification =====
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Functional classification based on **white matter tract infiltration**.

Focuses on:
  * **Uncinate fasciculus (UF)**
  * **Inferior fronto-occipital fasciculus (IFOF)**
  * **Corticospinal tract (CST)**
  * **Arcuate fasciculus**

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Primarily used in **awake craniotomy** and **tractography-based resection**.
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===== ▶ Kawaguchi Grading System =====
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Grading system based on **surgical complexity** and **depth of tumor invasion**:

  * **Grade I**: Confined to insula  
  * **Grade II**: Extends to opercula  
  * **Grade III**: Involves putamen/internal capsule  
  * **Grade IV**: Opercula + deep structures

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✔ Helps estimate risk of morbidity  
✔ Useful for predicting resectability
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===== 🧾 Classification Summary Table =====

^ Classification        ^ Basis                            ^ Primary Use                               ^
| Berger–Sanai         | Quadrant anatomy                  | Vascular risk, surgical corridor          |
| Yaşargil             | Topographic extension             | Spread to limbic/paralimbic structures   |
| Mandonnet–Duffau     | White matter tract infiltration   | Functional preservation, awake surgery   |
| Kawaguchi            | Depth and complexity              | Surgical risk and difficulty grading     |

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===== References =====
  * Berger MS, Sanai N. *Neurosurgery* (2010)  
  * Yaşargil MG. *Microneurosurgery Vol IVB* (1996)  
  * Mandonnet E, Duffau H. *Neurochirurgie* (2008)  
  * Kawaguchi T et al. *Neurosurgery* (2011)





Dominant insular tumor

Nondominant insular tumor

Despite the described [[Berger Sanai Classification]] of insular gliomas, other based on anatomical localization (Yasargil) or on extension within white matter tracts (Mandonnet and Duffau) are in use
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The study findings of Wang et al., suggest that the [[putamen]] classification is an independent predictor of survival outcome in patients with insular low-grade gliomas. This newly proposed classification allows preoperative survival prediction for patients with insular gliomas
((Wang Y, Wang Y, Fan X, Li S, Liu X, Wang J, Jiang T. Putamen involvement and
survival outcomes in patients with insular low-grade gliomas. J Neurosurg. 2016
Aug 26:1-7. [Epub ahead of print] PubMed PMID: 27564467.
)).

===== Insuloopercular glioma =====


see also [[insuloopercular glioma]].