Female, 42 years old, pregnant at 30 weeks gestation with two-day history of blurred vision and headache. Exam is consistent with a partial right third nerve palsy. A mass is present in the right middle cranial fossa with a broad base of attachment along the greater sphenoid wing measuring 42 x 28 mm transaxial and 37 mm craniocaudal. There is a thin cleft of CSF signal separating this lesion from the adjacent temporal lobe indicating extra-axial origin. The lesion itself demonstrates T1 isointensity and mild T2 hyperintensity relative to white matter, with mild diffusion restriction. The adjacent greater sphenoid wing and anterior clinoid process seem to be mildly thickened.This lesion induces significant regional and generalized mass effect with compression of the adjacent temporal lobe, leftward uncal herniation, and compression and leftward deviation of the mid brain. Edema is present within the right temporal lobe tracking superiorly into the right parietal lobe and the basal ganglia. There is a moderate generalized midline shift of the anterior brain structures, while posteriorly, the falx seems pushed towards the right. This may reflect competing mass effect between the tumor on the right, and the entrapped enlarged left lateral ventricle. The right lateral ventricle is partly effaced. The fourth ventricle is normal.Dedicated MRA images demonstrate tumor related mass effect upon the right MCA system with vessels displaced superiorly and draping over the large tumor. Nevertheless, the MCA vessels demonstrate normal caliber with no evidence of significant stenosis or occlusion. Along the posterior margin of the tumor, there is a serpiginous prominent venous structure which may reflect venous engorgement due to mass effect or increased drainage from the adjacent lesion. Elsewhere, assessment of the intracanal vasculature is within normal limits. No definite evidence of any intracranial aneurysm is detected within the limitations of technique.
A large extra-axial mass is present within the right middle cranial fossa with a broad base of attachment to the greater sphenoid wing. There are findings to suggest hyperostosis of the sphenoid and anterior clinoid process. Even without the benefit of IV contrast, the imaging findings are most suggestive of a large meningioma.This lesion induces significant regional and generalized mass effect with substantial edema tracking through the temporal lobe. There is right uncal herniation, a moderate midline shift to the left, effacement of the right lateral ventricle and entrapment/dilatation of the left lateral ventricle.MRA images demonstrate displacement of the right MCA vessels from their normal course but preservation of vessel patency. No evidence of significant vascular stenosis or occlusion is seen. No aneurysms are detected within the limitations of technique.