Malignant meningioma

Malignant meningioma is a rare, fast-growing tumor that forms in one of the inner layers of the meninges. Malignant meningioma often spreads to other areas of the body.
The World Health Organization classification system defines both grade II and grade III meningiomas as malignant. Historically, histological subtypes have also been used in classification including:

clear cell,
chordoid,
rhabdoid, and
papillary

Benign or low grade meningiomas include meningothelial, fibrous, transitional, psammomatous, angiomatous, microcystic, secretory, lymphoplasmacyte-rich, and metaplastic.