meningioma

Meningiomas are a diverse set of tumors arising from the meninges, the membranous layers surrounding the central nervous system. They arise from the arachnoid "cap" cells of the arachnoid villi in the meninges. These tumors usually are benign in nature; however, a small percentage are malignant. Many meningiomas produce no symptoms throughout a person's life, and if discovered, require no treatment other than periodic observation. Typically, symptomatic meningiomas are treated with either radiosurgery or conventional surgery. Historical evidence of meningiomas has been found going back hundreds of years, with some successful surgeries for their removal beginning in the 1800s.