case_images: PMC9909362_01
case_images: Sagittal (A) and axial (B) view of the contrasted CT images of the brain shows fluid density lesion in the posterior fossa region (red arrow).
case_images: cureus-0015-00000033579-i01.jpg
case_images: PMC9909362_01_cureus-0015-00000033579-i01.jpg
case_images: FIG1
case_images: A well-defined non-enhancing hypodense lesion at the retro-cerebellar area was seen on the Computed Tomography (CT) scan (Figures 1A, 1B), which strongly suggests an arachnoid cyst.
case_images: A cystic lesion in the posterior fossa (arrow A) with similar signal intensity as the CSF in the fourth ventricle (arrow B) shown in MRI in different views.. I: T1-weighted image, II: T2-weighted image, III: Flair sequence image, IV: Post-gadolinium image
case_images: cureus-0015-00000033579-i02.jpg
case_images: PMC9909362_01_cureus-0015-00000033579-i02.jpg
case_images: FIG2
case_images: The MRI showed the presence of a well-circumscribed left retro-cerebellar lesion which follows the CSF signal intensity in all sequences (Figure 2).