A brain tumor is usually a term for a collection, or mass, of abnormal cells in the brain. Brain tumors can be either cancerous (malignant) or non-cancerous (benign). When benign or malignant tumors grow, they may cause the pressure inside the skull to increase. This can cause brain damage, and it can be fatal.

Brain tumors can be categorized as primary or secondary. A primary brain tumor originates in the brain. Most primary brain tumors are benign. A secondary brain tumor, also called a metastatic brain tumor, occurs when the cancer cells spread to the brain from another organ, such as cancer affected lung or breast.

Primary Brain Tumors

Primary brain tumors originate in the brain. They can develop from:

Brain cells

The surrounding membranes around the brain, called meninges

Nerve cells

Glands

Primary tumors may be benign or malignant. In adults, the most usual types of brain tumors are gliomas and meningiomas.

Gliomas are tumors that develop from glial cells. These glial cells:

support the structure of your central nervous system

provide nutrition to the central nervous system

break down the dead neurons

clean cellular waste

The types of tumors that begin in glial cells are:

Astrocytic tumors such as Astrocytomas, that originate in the cerebrum and is often benign

Oligodendroglial tumors, which are usually found in the frontal temporal lobes

Glioblastomas, originate from the supportive brain tissue and are most aggressive

Meningiomas, those originating in the meninges

Schwannomas, which originates in the cells that produce the protective cover of nerves (myelin sheath) called Schwann cells

Most of meningiomas and schwannomascases occur in people between the ages of 40 and 70. Meningiomasmore often occur in women than in men. Schwannomascan occur equally in both men and women. Usually these tumors are benign, but maylead to complications because of their size and location. Cancerous meningiomas and schwannomas can turn very aggressive.

Other Primary Brain Tumors

Other primary brain tumors include:

Pituitary tumors, which are usually benign

Ependymomas, usually benign

Pineal gland tumors, which can be either benign or malignant

Craniopharyngiomas, which mostly occurin children and are benign and may have symptoms like changes in vision and premature puberty

Primary central nervous system (CNS) lymphomas, which are always malignant

Primary brain lymphomas, which are malignant

Primary germ cell tumors of the brain, which can be either benign or malignant

Secondary Brain Tumors

Secondary brain tumors make up the majority of brain cancers cases. They start in one part of the body and spread to the brain. The following cancers can lead to the brain:

lung cancer

breast cancer

skin cancer

kidney cancer