what is a meningioma brain tumor
A meningioma is a tumor that arises from the meninges â the membranes that surround your brain and spinal cord. Most meningiomas are noncancerous (benign), though rarely a meningioma may be cancerous (malignant).Some meningiomas are classified as atypical, meaning they're neither benign nor malignant but, rather, something in between.ost meningiomas are noncancerous (benign), though rarely a meningioma may be cancerous (malignant). Some meningiomas are classified as atypical, meaning they're neither benign nor malignant but, rather, something in between.