The majority of benign brain tumors arise from brain or brain-associated tissue (for example, nerve tissue, blood vessels). The following is a list of the most frequently diagnosed benign brain tumors:

• meningioma – tumor arising from the membranes covering the brain and spinal cord; this accounts for about 20% of brain tumors
• schwannoma (also termed acoustic neuroma) – tumor in the 8th cranial nerve arising from Schwann cells (insulating cells of the nervous system); this accounts for about 9% of all brain tumors
• pituitary adenomas – pituitary gland tumor; this accounts for about 8% of brain tumors
• hemangioblastomasa –  vascular tissue mass, sometimes cystic; this accounts for about 2% of brain tumors
• craniopharyngioma – a cystic tumor from cell remnants of Rathke’s pouch (nasopharynx), usually occurring in children; this accounts for about 1%-3% of brain tumors
• choroid plexus papilloma—choroid plexus tissue (the tissue responsible for the production of cerebrospinal fluid or CSF) mass that blocks cerebrospinal fluid flow, usually in children; this accounts for less than 1% of brain tumors

Other structures such as epidermoid and dermoid cysts (cysts that arise from epithelial cells, or lining cells of body organs and cavities) are considered to be benign tumors by many physicians because they can exert a mass effect (pressure) on brain tissue similar to actual brain tumors. These are rare “tumors.”