Presentation
Headache and memory problem.
Patient Data
The mass looks hyperdense to normal brain on native study with no calcification, brightly and homogeneously enhance post contrast adminstration.
Extra-axial, left-sided para-falcine mass lesion with broad-base relation to the anterior free edge of the posterior falx cerebri, the mass measures about (65 x 56 x 50 mm) (CC*AP*TRA) maximal dimensions, no perilesional vasogenic edema, no overt brain invasion, intra- or trans-osseous extension
It is well-circumscribed with noticeable arachnoidal cleavage plane and macro lobulation at the inferolateral aspect, appears relatively isointense on T1WI and T2WI to the gray matter, and shows intense homogenous contrast enhancement, the mean ADC value of 0.84 × 10-3 mm2 s-1 favors low-grade tumor. The mass exerts a significant pressure effect manifesting as:
swollen left supratentorial brain with effaced sulci mainly posteriorly, pressure effect on the left transverse sinus, no thrombosis
stretching the splenium of the corpus callosum over its anteromedial aspect
buckling the parietal GM/WM laterally almost effacing the left atrium of the lateral ventricle resulting in dilated/trapped temporal and occipital horns with trans-ependymal CSF seepage around the trapped ventricle
left lateral (anterior and posterior) descending trans-tentorial herniation: the uncus is herniated downward into the ipsilateral crural cistern, and the para-hippocampal gyrus/part of the mass is displaced downward into the posterolateral part of the tentorial incisura almost effacing the perimesencephalic cistern, rightward shift and mild rotation of the brainstem was noted, no frank central or sub-falcine herniation, no tonsillar ectopia
No brain stem edema, hemorrhagic or posterior circulation infarct (despite the pressure effect on the P2: post-communicating segment of the left posterior cerebral artery), no other mass lesion
MRA, MRV: no occlusion or severe focal stenosis, no aneurysm or vascular malformation. Deep cerebral veins and dural venous sinuses enhance normally.
Case Discussion
The constellation of finding favors low-grade left para-falcine meningioma with significant mass effect resulting in trapped temporal and occipital horns and left lateral transtentorial herniation.