case_images: PMC10408629_01
case_images: Non-contrast head MRI. Black arrow indicates right Sylvian fissure lipoma encasing right MCA. Axial scans show different signal intensity of the lesion in selected MRI sequences. (a) T1W CSE hyperintense lesion. (b) T2W FSE hyperintense lesion. (c) FLAIR hyperintense lesion. (d) SWI hypointense lesion with blooming artifacts. (e) DWI hypointense lesion. MRI: Magnetic resonance imaging, MCA: Middle cerebral artery, T1W CSE: T1W conventional spin echo, T2W FSE: T2W fast echo spin, SWI: Susceptibility weighted imaging, DWI Diffusion weighed imaging. FLAIR: Fluid-attenuated inversion recovery.
case_images: SNI-14-268-g001.jpg
case_images: PMC10408629_01_SNI-14-268-g001.jpg
case_images: F1
case_images: Diffusion-weighted imaging (DWI) did not show diffusion restriction [Figure 1].
case_images: CT angiography in 3D projection of intracranial arteries. The gray arrow indicates the location of fusiform dilatation of the right MCA trifurcation. CT: Computed tomography, MCA: Middle cerebral artery.
case_images: SNI-14-268-g002.jpg
case_images: PMC10408629_01_SNI-14-268-g002.jpg
case_images: F2
case_images: Emergency head computed tomography (CT) angiography of the cerebral arteries was performed revealing unruptured fusiform aneurysm of the right MCA located at the border of M1 and M2 segments, extending the length of about 6 mm with maximal radius of the vessel up to 4 mm and with the anatomical variation of the right MCA in the form of trifurcation of the M2 branches was discovered [Figure 2].
case_images: Non-contrast head CT scan in axial projections showing 3 consecutive scans 2,5 mm apart. The black arrow on images (a-c) show a cross-section at different levels of the lesion located in the right Sylvian fissure corresponding to a lipoma and encasing the right MCA. CT: Computed tomography, MCA: Middle cerebral artery.
case_images: SNI-14-268-g003.jpg
case_images: PMC10408629_01_SNI-14-268-g003.jpg
case_images: F3
case_images: Distal half of M1 segment and proximal part of M2 segment of the right MCA were encased by extremely hypodense mass lesion 10 x 13 x 13 mm (-90 to -100 HU) identified as a fat, arranged in Sylvian fissure [Figure 3].
case_images: Axial T1W FS sequence in non-contrast head MRI. The black arrow indicates adipose tissue. MRI: Magnetic resonance imaging.
case_images: SNI-14-268-g004.jpg
case_images: PMC10408629_01_SNI-14-268-g004.jpg
case_images: F4
case_images: T1W Fat Saturation (T1W FS) sequence, in which there was complete suppression of the fatty tissue [Figure 4]. Taking into account the whole diagnostic pathway, perianeurysmal Sylvian fissure lipoma encasing right MCA trifurcation was diagnosed.