Yasargil Classification of Insular Glioma
Limited to the insula (Yasargil type 3a)
Reach the perisylvian operculum (type 3b)
other paralimbic areas, namely the orbitofrontal and temporopolar regions (type 5),
operculo-insular region and the fronto-orbital, including the perforated substance (white arrow), temporopolar and hyppocampal regions, type 5 B 1).
Magnetic resonance imaging (MRI) with T2-weighted and Fluid Attenuated Inversion Recovery (FLAIR) images best delineates the extent of tumour infiltration, which can be limited to the insular lobe (Yasargil type 3a) or reach the perisylvian opercula (type 3b) and other paralimbic areas, namely the orbitofrontal and temporopolar regions (type 5), with or without involvement of core limbic structures 2).
Although the classification of insular glioma has been established based on the anatomical location in order to facilitate personalized surgical resection, the diagnosis based on anatomical and functional characteristics becomes more complex when insular tumors extend into either the frontobasal brain region and/or the temporal lobe, as part of the limbic system.