There are different classifications of brain tumors. One is the division of all brain tumors in the primary and secondary.
The primary tumor
Primary tumors originate from the very fabric of the brain tissue or adjacent to it, such as tissue mater, cranial nerves, pituitary and pineal gland. The cause of primary tumors is the appearance of anomalies in the DNA of brain cells. The cause of these anomalies are mutations.
Primary brain tumors are less common, compared with secondary tumors. These tumors occur in the brain by metastasis from other cancers.
There are many different types of primary brain tumors. In this case, the name of the tumor is the name of the tissue in which it evolved:
Acoustic neuroma (schwannoma)
Astrocytomas, also known as a glioma, which includes anaplastic astrocytoma and glioblastoma
Secondary tumors (metastases TN) arise in the metastasis of many cancers of other organs. In some cases, the metastatic tumor in the brain shows up on the background of an existing tumor in another organ. In other cases, a tumor can be the first sign of cancer in any organ.