Gangliocytoma is a rare type of central nervous system (CNS) tumor made up of mature neurons. Gangliocytomas may occur in all age groups but most often occur in people between the ages of 10 and 30. The most common site is the temporal lobe of the brain, but they can arise anywhere in the CNS including the cerebellum, brainstem, floor of the third ventricle, and spinal cord. They are among the most frequent tumors associated with epilepsy. Signs and symptoms may depend on the tumor's location and may include seizures (most commonly); increased brain pressure; endocrine disorders; and focal symptoms. Gangliocytomas are generally slow-growing and usually do not become malignant. Treatment involves surgical removal of the tumor.