Types of Brain Cancer

There are several types of brain cancer. The brain itself can be the source of several types of tumors, called primary brain tumors. However, it can also harbor cancers that originate in some other organ or tissue but then spread, either directly or by the bloodstream, to the brain. This page has information about each. The first section below discusses the general types of cancer affecting the brain. The second section below presents the types of brain cancer which originate in the brain tissue itself, primary brain tumors.

General Types of Brain Cancer

Metastatic Cancers: Many types of cancer can spread through the lymphatic system or bloodstream to distant parts of the body. This process is called metastasis. These metastatic cancers can spread to numerous places including the brain. These cancers do not originate in the brain tissue itself, but they can begin to grow in the brain and cause injury to the brain tissue and thus can cause neurological symptoms just like any other type of cancer in the brain. There are many types of cancer that can spread to the brain but some of the most common types include breast cancer, lung cancer, melanoma (of the skin) and others. These metastatic cancers are actually the most common type of brain cancer, more common in the general population than primary brain tumors.

Cancers That Grow Into the Brain From Nearby (Direct Extension): Some cancerous tumors can initially form in another tissue outside but near the brain and then grow into the brain as it enlarges. These are generally tumors of the head and neck, particularly those near the base of the skull and the nasal and sinus passages. Examples include malignant meningiomas (rare cancers of the membrane covering the brain), oropharangeal and nasopharyngeal cancers such as adenocarcinomas and squamous cell carcinomas, chondrosarcomas, and others.

Primary Brain Tumors: Finally, there are malignant tumors which can originate from the cells of the brain itself. These brain tumors are truly types of brain cancer in that they are cancers of the brain tissue itself, not of some other organ and tissue which has spread to the brain. While they are more rare in the general population than metastatic cancer, they are an important disease that affects thousands of people each year. The sub-types of primary brain tumors are discussed further below.

Types of Brain Cancer: Primary Brain Tumors

Gliomas: Gliomas are by far the most common types of primary brain cancers. Glioma is a general term for tumors that originate from the glial cells, which are the "helper cells" of the nervous system. These cells, including astrocytes, oligodendrocytes and ependymal cells, all help in different ways to regulate the internal environment of the brain so that the neurons (the primary action cells of the nervous system) are comfortable and work normally. The most common type of glioma is an astrocytoma which is derived from astrocytes. Oligodendrogliomas and ependymomas arise from oligodendrocytes and ependymal cells, respectively.

All types of gliomas can vary in how benign or malignant they are. They generally vary on a 4 point scale that characterizes them as far as their aggressiveness and invasiveness. Grade 3 and 4 gliomas are considered malignant gliomas and are thus brain cancers, whereas Grade 1 and 2 tumors are considered to be on the benign end of the spectrum. Grade 4 gliomas are the most aggressive, fast growing and invasive and are sometimes called Glioblastoma Multiforme, or GBM for short.

Primitive Neuroectodermal Tumors (PNET): PNET's are a class of tumors which can occur in the brain. They include such tumors as pinealoblastoma, neuroblastoma and medulloblastoma which occurs primarily in children.

Primary CNS Lymphoma: Lymphoma is a tumor of white blood cells that most commonly involves other lymphoid organs such as the lymph nodes and spleen. However, they can occur in the central nervous system (CNS).

Choroid Plexus Carcinoma: The choroid plexus is a tissue in the ventricles of the brain, the fluid filled spaces within the brain. While benign papillomas are the most common type of tumor of the choroid, they can form malignant choroid plexus carcinomas rarely.