It isn't clear what causes a meningioma. Doctors know that something alters some cells in your meninges — the membranes that form a protective barrier around your brain and spinal cord — to make them multiply out of control, leading to a meningioma tumor. But whether this occurs because of genes you inherit, things you're exposed to in your environment, hormones or a combination of these factors remains unknown.

May 02, 2014