PMC9840568_01
The Sylvian lipoma shows a markedly high signal intensity on axial T1-weighted imaging (A) and fluid-attenuated inversion recovery imaging (B), along with a slightly high signal intensity on axial T2-weighted imaging (C) on preoperative magnetic resonance imaging. The Sylvian lipoma shows signal supression on axial diffusion-weighted imaging (D) and the corresponding apparent diffusion coefficient map (E). The anterior temporal cortex adjacent to the Sylvian lipoma shows hypometabolism on fluorodeoxyglucose positron emission tomography/computed tomography (F)
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Fig1
Memory Scale-Revised (WMS-R) demonstrated no memory decline (verbal memory 94, visual memory 103, general memory 96, attention/concentration 105, delayed recall 96) before surgery. Magnetic resonance imaging (MRI) showed a mass lesion in the left Sylvian fissure with homogeneous hyperintensity on both T1-weighted and T2-weighted images but no diffusion restriction on diffusion-weighted images/apparent diffusion coefficient maps (Fig. 1).
Intraoperative electrocorticography using an epidural electrode as reference shows the high-amplitude spikes on the ventral side of the anterior temporal lobe
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Fig2
The ioECoG showed IEDs at the strip electrodes located on the anterior lateral temporal lobe (Fig. 2). Therefore, we performed the anterior temporal lobectomy (ATL) 3 cm from the temporal tip without removing the Sylvian lipoma (Fig. 3).
The intraoperative image after the anterior temporal lobectomy shows the remaining temporal lobe, hippocampus, and Sylvian lipoma covered with the pia mater of the Sylvian fissure
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Fig3
The ioECoG showed IEDs at the strip electrodes located on the anterior lateral temporal lobe (Fig. 2). Therefore, we performed the anterior temporal lobectomy (ATL) 3 cm from the temporal tip without removing the Sylvian lipoma (Fig. 3).
After the anterior temporal lobectomy, the Sylvian lipoma is shown isolated from the temporal lobe on axial diffusion-weighted (A), T2-weighted (B), and fluid-attenuated inversion recovery imaging (C)
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Fig4
Postoperative MRI demonstrated the preserved Sylvian lipoma and branches of the middle cerebral artery within the Sylvian fissure (Fig. 4).