NCIt related terms : Meningioma, anaplastic; Meningioma, malignant;
NCIt definition : A WHO grade III meningioma characterized by the presence of malignant morphologic
features, including malignant cytology and a very high mitotic index (20 or more mitoses
per ten high power fields).;
Alternative definition : NCI-GLOSS: A rare, fast-growing tumor that forms in one of the inner layers of the
meninges (thin layers of tissue that cover and protect the brain and spinal cord).
Malignant meningioma often spreads to other areas of the body.;