How are meningiomas histologically graded?
WHO I : meningioma (88-95%), WHO II : atypical meningioma (5-6%), WHO III : malignant meningioma (1%), WHO IV : meningioma with sarcomatous degeneration (rare)
Most meningiomas are sporadic. Can you name two situations which predispose to multiple meningiomas?
Previous cranial irradiation and neurofibromatosis type II (NF2).
The large extra-axial mass ( * ) results in significant midline shift with displacement of the anterior falx towards the right along with anterior subfalcine herniation (blue arrows). Previous craniotomy is best seen on bone window (green arrows).