Brain tumors are categorized as primary or secondary. A primary brain tumor originates in your brain. Many primary brain tumors are benign. A secondary brain tumor, also known as a metastatic brain tumor, occurs when cancer cells spread to your brain from another organ, such as your lung or breast.

1- Primary Brain Tumors
Primary brain tumors originate in your brain. They can develop from your:
– Brain cells
– The membranes that surround your brain, which are called meninges
– Nerve cells
– Glands
Primary tumors can be benign or cancerous. In adults, the most common types of brain tumors are gliomas and meningiomas.

Gliomas are tumors that develop from glial cells. These cells normally:
– Support the structure of your central nervous system
– Provide nutrition to your central nervous system
– Clean cellular waste
– Break down dead neurons
Gliomas can develop from different types of glial cells.

– Astrocytic tumors such as astrocytomas, which originate in the cerebrum
– Oligodendroglial tumors, which are often found in the frontal temporal lobes
– Glioblastomas, which originate in the supportive brain tissue and are the most aggressive type
– Other primary brain tumors
– Pituitary tumors, which are usually benign
– Pineal gland tumors, which can be benign or malignant
– Ependymomas, which are usually benign
– Craniopharyngiomas, which occur mostly in children and are benign but can have clinical symptoms like changes in vision and premature puberty
– Primary central nervous system (CNS) lymphomas, which are malignant
– Primary germ cell tumors of the brain, which can be benign or malignant
– Meningiomas, which originate in the meninges
– Schwannomas, which originate in cells that produce the protective cover of your nerves (myelin sheath) called Schwann cells
Most meningiomas and schwannomas occur in people between the ages of 40 and 70. Meningiomas are more common in women than men. Schwannomas occur equally in both men and women. These tumors are usually benign, but they can cause complications because of their size and location. Cancerous meningiomas and schwannomas are rare but can be very aggressive.

2- Secondary Brain Tumors
Secondary brain tumors make up the majority of brain cancers. They start in one part of the body and spread, or metastasize, to the brain. The following can metastasize to the brain:
– Lung cancer
– Breast cancer
– Kidney cancer
– Skin cancer
Secondary brain tumors are always malignant. Benign tumors don’t spread from one part of your body to another.