Benign brain tumors are abnormal collections of cells which reproduce slowly and are most often isolated from surrounding normal brain tissue.

These tumors grow slowly, do not spread to other parts of the brain and are generally easier to excise the malignant tumors. Malignant tumors grow and multiply rapidly. It is difficult to delineate these tumors compared to surrounding normal brain tissue. For this reason it is difficult to remove them completely without damaging the surrounding brain.

We can classify benign and malignant tumors in different groups, depending on the type of cells from which they emerge.

Can be classified as benign tumors following:

* Chordomas, whose origin lies in embryonic cells of the spinal cord or the base of the cranial nerve;

* Hemangioblastomas, which begin in blood vessels;

* Meningiomas, starting in the membrane covering the brain;

* Osteomas in the bone of the skull;

* The pinealomas in the pineal gland;

* The pituitary adenoma in the pituitary;

* The schwannomas, in cells that surround nerves.

Some types of tumors such as meningiomas (arising from the meninges, the lining surrounding the brain) or germ cell tumors can be benign in some cases and malignant in others. This article focuses on brain tumors malignant (cancerous). Brain cancers are relatively rare but often fatal.

They are the second leading cause of mortality among children under 20 years. Malignant brain tumors the most common are gliomas, where cells called glia (support cells for nerve cells) become cancerous. Glioblastoma multiforme is the most common of the gliomas. Glioblastoma multiforme and anaplastic astrocytoma are fast-growing gliomas. Oligodendroglioma, another type of glioma, is also rare, occurs mainly in adults. Gliomas make up between 50% and 60% of all brain tumors (malignant and benign), children and adults alike. Medulloblastoma, which is derived cells of the spinal cord at the base of the brain, is the type of brain tumor most common in children. It occurs most often before puberty. Finally, sarcoma and adenocarcinoma are two kinds of extremely rare brain tumor.