Meningioma - sphenoid wing - typical
CT and MRI demonstrate characteristic appearances of a left sphenoid wing meningioma. The mass is well circumscribed and extraaxial with a broad dural base. It is isodense to brain on CT and enhanced relatively vividly. On MRI it is isointense on both T1 and T2 images to grey matter, and again demonstrates enhancement.
In this cases there is little differential diagnosis. It is remote from the the pituitary fossa, making a solid craniopharyngioma unlikely. Signal characteristics are not those of a chondroid tumor.
The sections show fragments of tumor, which shows variable and up to densely collagenous fibrosis. The tumor is present as sheets, islands, and nests of elongate cells, with poorly defined cytoplasmic outlines. Nuclei are oval and fairly regular, sometimes with cytoplasmic inclusions. No tumor necrosis is identified, there are no areas of tumor cell "sheeting", with no foci showing macronucleoli. No cerebral tissue is identified.
Final diagnosis: Meningioma, WHO grade 1