Case #29

CT

• Large, mildly hyperattenuating extra-axial mass centered at midline in the anterior cranial fossa
• Corresponding calcification and adjacent hyperostosis along the olfactory groove
• Vasogenic edema in the adjacent left frontal lobe
• Associated mass effect on the frontal lobes, genu of the corpus callosum, and frontal horns of the lateral ventricles without herniation or hydrocephalus

MRI

• T1 hypointense, T2 isointense extra-axial mass centered in the anterior cranial fossa overlying the olfactory groove
• Diffuse enhancement with radiating internal vascularity
• Diffuse internal restricted diffusion
• Areas of susceptibility artifact corresponding with the areas of calcification seen on CT
• T2/FLAIR signal hyperintensity in the adjacent left frontal white matter
• Posterior displacement of the anterior cerebral arteries
• Possible contacting of the prechiasmatic optic nerves along the inferior margin of the mass