The type of intracranial tumor often depends on the cranial anatomy. Our human skull is composed of: skull, brain tissue, ventricular system, and cerebrovascular system. This leads to different types of tumors. The common intracranial tumors are: Cranial tumors: originate from abnormal proliferation of cells in the skull. Meningioma: originates from the arachnoid membrane on the surface of the brain. It accounts for about 20% of intracranial tumors. Glioma: originates from abnormal proliferation of glial cells. It accounts for about 50% of intracranial tumors. Ventricular meningioma: originates from ventricular ventricular membrane cells. Nerve sheath tumor: derived from abnormal proliferation of nerve sheath cells Pituitary adenoma: derived from pituitary gland cells. It accounts for about 10% of intracranial tumors. Arteriovenous aneurysm, vascular malformation: These are not true tumors, but are vascular masses with outwardly bulging or abnormal vessel walls. Bleeding has occurred. Congenital tumors: such as epidermoid cysts, teratomas, etc.