Findings
Pre- and postcontrast MRI of the brain demonstrates an approximately 5 cm (AP) x 6 cm (TRV) x 3.5 cm (CC) homogeneously enhancing extra-axial mass arising from the anterior skull base. There is superior displacement of the frontal lobes associated with vasogenic edema. There is evidence of hyperostosis involving the anterior skull base. The posterior aspect of the mass extends to the anterior portion of the sella. The mass extends anteriorly along the planum sphenoidale and extends along the anterior cranial fossa and involves the olfactory grooves. The anterior portion of the mass extends to approximately the level of the cribriform plate. The posterior aspect of the mass abuts the anterior portion of the optic chiasm with slight inferior displacement.
The mass partially effaces the anterior corpus callosum and frontal horns of the lateral ventricle and is associated with mild ventriculomegaly. The mass does not involve the cavernous sinus. There is evidence of intratumoral flow voids suggesting hypervascularity. Sagittal images do suggest erosion of the anterior skull base with involvement of the superior nasal cavity.
Conclusions
Large extra-axial homogeneously enhancing mass arising from the anterior skull base with evidence of bone erosion of the anterior skull base with involvement of the superior aspect of the nasal cavity. Findings consistent with large anterior skull base meningioma with involvement of the planum sphenoidale and abutting anterior optic chiasm.