The etiology of primary intracranial tumors are unknown in > 95 % of the cases.
- Neurofibromatosis type 1 is associated with low-grade gliomas (especially astrocytoma in optic chiasma–hypothalamus).
- Neurofibromatosis type 2 is associated with Schwannoma, meningioma and glioma (especially ependymoma).
- Tuberous sclerosis is associated with astrocytoma (subependymal giant cell–astrocytoma).
- Von Hippel-Landau's syndrome is associated with capillary hemangioblastoma (5).
- Turcot syndrome is associated with glioblastoma and medulloblastoma.
- Li-Fraumen syndrome is associated with glioblastoma.
Ionizing radiation is the only risk factor that can be associated with certainty to the development of primary, intracranial tumors. Radiation of the cranium, even in small doses, increases the risk of developing meningiomas by a factor of 10 and the risk of developing glioma by a factor of 3–7, with a latency period of 10–30 years after exposure.
Sofar, there is no definite connection between long term use of mobile phones and development of gliomas, meningiomas and vestibular schwannomas.
No certain connection has been demonstrated between increased incidence of intracranial tumors and tobacco, alcohol, exposure to high voltage cables, use of hair color products or head injuries.