It isn't clear what causes a meningioma. Experts know that something changes some cells in the meninges. The changes makes them multiply out of control. This leads to a meningioma. Being exposed to radiation as a child is the only known environmental risk factor for getting meningioma. Read more from Mayo Clinic here: https://www.mayoclinic.org/diseases-conditions/meningioma/symptoms-causes/syc-20355643

It's only human nature to search for a cause when diagnosed with a brain tumor. "How could this have happened?" is a question that I think everyone must ask themselves.

@researcher0, have you recently been diagnosed with a meningioma?