A brain tumor is a mass or growth of abnormal cells in the brain or spinal cord. Many brain tumors are able to disrupt the function of the brain. Others, however, are less harmful.
Brain tumors are either malignant (harmful) or benign (nonharmful). By definition, malignant tumors are more aggressive than benign tumors.
In benign tumors, the mass of abnormal cells does not contain cancer cells. Benign brain tumors grow slowly and tend not to spread from the original growth site. They are also more common than malignant tumors.
In fact, according to the American Brain Tumor Association (ABTA), around two-thirds of all new brain tumors are benign.
Malignant brain tumors contain cancer cells and tend not to have clear borders. These can grow rapidly and spread to other parts of the brain, which makes them more dangerous.
The American Cancer Society (ACS) group the statistics for brain tumors with those for tumors of the spinal cord. They estimate that healthcare professionals will diagnose up to 23,820 malignant primary brain and spinal cord tumors in 2019.
In this article, we look at both main categories of brain tumors and their symptoms.
Doctors may also refer to a tumor based on the site from which the cells originated.
If the tumor began in the brain, for example, it is a primary brain tumor. If it began in another part of the body and spreads to the brain, it is a secondary (or metastatic) brain tumor.
Each type of tumor has a range of different characteristics and subtypes, and a tumor may consist of more than one type of cell.
In 2016, the World Health Organization (WHO) officially reclassified all types of brain and spinal cord tumors. There are now over 120 types of brain and spinal cord tumors that affect different types of cells.
Acoustic neuroma or vestibular schwannoma
This type of cancer forms on the sheaths that protect nerves. It often affects the nerves involved in hearing.
These benign tumors may form at the base of the spine or skull, or near the pituitary gland. However, they may become malignant chondrosarcomas.
Central nervous system lymphoma
This is a highly aggressive type of cancer that affects the immune cells in the lymph nodes. It is most common in people ages 60–80, but it is becoming more common in young adults.
These tumors develop near the optical nerve, at the base of the brain, and near the pituitary gland. They develop from cells in the pituitary gland.
Germ cell tumors
These develop from germ cells, mainly in people around 11–30 years of age. They can be either benign or malignant.
A glioma is a tumor that starts in the supportive tissue of the brain. These affect three different types of cells: astrocytes, ependymal cells, and oligodendrocytes.
They can develop in several locations across the brain and nervous system.
These are overgrowths of blood vessels in the skin or internal organs. In the brain, there are two main types.
Hemangioblastomas are slow-growing, benign tumors. Hemangiopericytomas develop in the meninges, the membrane of the brain, and can spread to distant organs such as the lungs.
These are masses that grow from fatty tissue. They are benign and very rarely cause symptoms or health problems.
This is more common in children. Medulloblastomas develop in embryonic cells early as an embryo develops.
They always develop at the lower portion of the brain at the back. They usually spread, but rarely outside of the brain and spinal cord.
These usually develop inward from the protective layer that covers the brain and spinal cord, applying pressure.
They account for around one-third of all tumors that start in the brain. Most are noncancerous.
This is a tumor of the nerve fibers. These develop due to a genetic condition called neurofibromatosis.
Neuronal and mixed neuronal-glial tumors
These develop from groups of nerve cells called ganglion cells. They are benign and grow slowly.
Pineal and pituitary tumors
These develop on glands that play essential roles in hormone secretion.
Primitive neuroectodermal tumor
These closely resemble medulloblastomas under a microscope but grow on a different part of the brain. They are rare but highly malignant and tend to spread.
Symptoms of brain tumors vary depending on the type of tumor and its location.
The following symptoms may occur slowly and gradually get worse. They may also develop quickly in the form of a seizure.
Common symptoms of brain tumors include:
- persistent headaches
- problems with vision
- nausea, vomiting, and general drowsiness
- issues with short term memory
- speech problems
- coordination issues
- personality changes
However, some people experience no symptoms at all.
According to the ACS, around half of people with a brain tumor experience persistent headaches. The ACS also says that up to half of all people with a brain tumor experience a seizure at some point.
If you have been diagnosed with having a brain tumor or experiencing symptoms, learn more about how we can help by checking out our services.