Cancers affecting the brain and the spinal cord are collectively known as nervous system cancers. Together, the brain tissue and the spinal cord make up the central nervous system (CNS). The CNS is responsible for elaboration and transmission of specific functions such as thought, speech, and body movements. When a tumor grows in the CNS, it can affect a person’s thought process, their speech, or their movement.
There are two types of brain tumors: primary and secondary. Primary brain tumors start in the brain and can either be low-grade, or high-grade tumors. A low-grade tumor grows slowly, but has the potential to turn into a high-grade tumor. A high-grade tumor is more likely to grow faster.
Secondary brain tumors, also known as brain metastases, are more common than primary brain tumors. These generally start in another part of the body (such as the breast, colon, liver) and then spread to the brain. Tumors can also be benign.. Both of benign and malignant tumors cause signs and symptoms and need treatment. Benign tumors grow and press on nearby areas of the brain but rarely spread to other parts of the brain. Malignant tumors, on the other hand, can spread to other parts of the brain.
Types of brain tumors:
There are many types of brain and spinal cord tumors that can form in different areas of the brain and the spinal cord. In general, gliomas are the most common type of brain tumor.
A glioma is a tumor that grows from a glial cell (a supportive cell in the brain). A glioma is given a grade that represents how much the tumor looks like a healthy brain tissue. The higher the grade, the more likely the tumor will grow quickly. The types of gliomas are:
- Astrocytoma: The most common type of glioma. It begins in cells called astrocytes located in the cerebrum or cerebellum. There are four grades of astrocytoma namely Grade I, II, III and IV. Grade IV corresponds to the worst case, i.e. glioblastoma.
- Oligodendroglioma: This type of tumor develops from cells called oligodendrocytes which make up myelin.
- Mixed glioma: This type of tumor is made up of more than one of the glial cell types
- Ependymoma: This type of tumor begins in the passageways of the brain where the cerebrospinal fluid is made and stored.
- Brain stem glioma: This type of tumor begins in the glial cells located in the brain stem
Non-glioma tumors are those that arise from cells in the brain that are not part of the glial or supportive tissue. Types of non-glioma tumors include:
- Meningioma: This type of tumor is the most common primary brain tumor and begins in the meninges.
- Pineal gland and pituitary gland tumors that are located in the pineal gland and pituitary gland
- Primary CNS lymphoma: This is a type of lymphoma that begins in the lymphatic system inside the cerebrum.
- Medulloblastoma: This type of tumor begins in the granular cells in the cerebellum.
- Craniopharyngioma: This type of tumor begins near the pituitary gland located near the base of the brain.
- Acoustic schwannoma: This type of tumor begins in the vestibular nerve, which is located in the inner ear. This nerve controls balance.