Meningioma

Meningioma, also known as meningeal tumor, is typically a slow-growing tumor that forms from the meninges, the membranous layers surrounding the brain and spinal cord; many cases remain asymptomatic, and symptoms when present depend on the tumor's location and result from pressure on nearby tissue. It occurs in about 1 per 1,000 people in the United States, usually in adults, affects women roughly twice as often as men, and is graded by the World Health Organization as grade 1, 2, or 3; risk factors include ionizing radiation and family history, and treatment ranges from observation to surgery and radiation therapy, with a 95 percent ten-year survival rate after complete removal.