Brain cancer is rare and makes up only about 1% of all cancer cases in the United States. However, it’s also the leading cause of cancer death in males younger than 40 years of age. There are many different types of brain tumors that are organized into one of two categories: malignant or nonmalignant.
Here, we’ll discuss the most common types of brain tumors along with common symptoms, diagnosis, and treatment.
Not all brain tumors are the same. When classifying brain tumors, it’s crucial to distinguish between malignant and nonmalignant (benign) as this determines treatment and management. Malignant brain tumors are made up of cancerous tissue and benign tumors are made up of noncancerous tissue. But that doesn’t mean benign tumors don’t cause problems. They can still cause various symptoms and may require surgery or further treatment.
Brain tumors are further classified based on where they originated. Primary brain tumors start in the central nervous system (CNS) and secondary brain tumors start from outside the CNS. Secondary brain tumors are metastatic, meaning that cancer has spread to the brain from another part of the body, such as the lung or breast.
Metastatic brain tumors are the most common type in adults. Up to one quarter of people who die from cancer have evidence of brain metastases. The most common primary cancers that metastasize to the brain are lung, breast, and melanoma.
There are multiple categories of primary brain tumors, which depend on the type of brain cell they come from as well as the location in the brain or spinal cord. They can further be broken down into malignant and nonmalignant types.
There are several different types of cancerous brain tumors, including gliomas (including Glioblastoma multiforme), medulloblastoma, pineal gland tumors, and CNS lymphoma. Keep in mind that many brain tumors can be found on a spectrum of low grade to high grade, meaning some tumors with the same name can be cancerous or noncancerous depending on their growth pattern and rate.
Gliomas are a broad category of brain tumor as they contain multiple subtypes of brain tumors based on the type of glial cell from which they originate. These tumors typically occur in the lobes of the cerebrum. Gliomas can be differentiated into astrocytomas (which includes glioblastoma multiforme or GBM), ependymomas, oligodendrogliomas, and mixed gliomas.
These tumors originate from a type of brain cell called an astrocyte. These tumors can be relatively slow-growing in nature, or low grade (grade I or II) or more aggressive, high grade (III or IV).
GBM is recognized as a high-grade astrocytoma (grade IV) and is typically very aggressive in nature. It’s the most commonly diagnosed malignant primary brain tumor in the United States. GBM is more common in males, and risk increases with age. While treatment therapies continue to improve, the 5-year survival rate for GBM is only 7%.
These tumors are made up of oligodendrocyte cells, and are most commonly found in the frontal lobes of the brain.
These tumors are made up of a mixture of astrocytes and oligodendrocytes.
These are tumors that start in the lining of the ventricles and are more common in children.
This type of brain tumor typically grows in the cerebellum, the area at the base of the brain that forms around the brainstem. It’s more common in children but can also be found in adults on rare occasion.
These are rare tumors, especially in adults. The pineal gland is responsible for producing melatonin. There are several different types of pineal gland tumors that range from low grade to high grade.
These tumors can be either primary or secondary. They’re rare overall but can be seen in those with weak immune systems and conditions including AIDS or in those who have undergone organ transplant.
There are several types of primary brain tumors that are considered nonmalignant, or benign. However, these types of brain tumors can still be life-altering and cause symptoms. Also, keep in mind that while these tumors are broadly classified as noncancerous, some types can become cancerous (although it’s rare).
These tumors are not exactly composed of brain tissue but rather come from the meninges, which is a tissue that surrounds, supports, and protects the brain and spinal cord. Meningiomas are the most common benign brain tumor, comprising up to half of benign brain tumors. They’re usually slow-growing and are rarely cancerous.
The pituitary gland is a small hormone-producing structure located in the sella turcica of the brain. Pituitary tumors are relatively common and frequently cause no symptoms. Up to 25% of people may have a pituitary tumor and not know it. While the vast majority of pituitary tumors are benign, very rarely, pituitary tumors can become cancerous.
Similar to pituitary tumors, craniopharyngiomas also occur in the sellar region. They are benign epithelial tumors, and while they’re more commonly considered to occur in children, up to half of cases occur in adults.
These are nerve sheath tumors that originate from Schwann cells, which are covered with myelin, a protective covering over nerve cells. A common type of Schwannoma is a vestibular schwannoma, or acoustic neuroma, which is a Schwannoma that surrounds the vestibulocochlear nerve and can significantly affect hearing and balance.
Generally, men are more at risk to develop the majority of types of brain tumors, except for meningiomas, which are more common in women.
Up to 5% of brain tumors are associated with genetic conditions such as Li-Fraumeni syndrome, neurofibromatosis, tuberous sclerosis. Ionizing radiation is also a recognized risk factor for the development of some brain tumors. Certain viruses like Epstein-Barr virus have also been linked to a higher risk of CNS lymphoma.
Headache is the most common symptom for different types of brain tumors. This can be due to pressure on the brain, depending on tumor size, and if there’s surrounding swelling.
While headache is the most common symptom of a brain tumor, most headaches aren’t caused by a brain tumor. However, the following characteristics of a headache can be a sign that something more serious is going on:
Other symptoms of a brain tumor can include:
To diagnose a brain tumor, clinical history is crucial. This includes information about the timing and severity of symptoms along with any family or personal history of other cancers. Physical exams can reveal various neurological findings that may indicate a specific location in the brain that has been affected by a tumor.
Imaging is indispensable for the diagnosis of all types of brain tumors. Computed tomography (CT) of the head is typically the first imaging study done as it can help rule out certain conditions, such as brain bleeding and swelling.
Magnetic resonance imaging (MRI) is the best imaging procedure for all types of brain tumors. This type of brain scan is not only crucial in the detection of primary brain tumors, but it can also help in early detection for brain metastasis. The gold standard for diagnosing primary brain tumors is biopsy with brain surgery.
While workup for brain masses can result in a diagnosis of a brain tumor, there are many other conditions that can present similarly to certain types of brain tumors. For example, some infections, such as an abscess or parasitic infection, can appear as a brain mass on imaging.
Some inflammatory diseases, like multiple sclerosis or various autoimmune conditions, and vascular changes or blood vessel abnormalities can present similarly. Further tests — including bloodwork, CSF studies, and imaging — can help differentiate between a brain tumor and other conditions.
After diagnosis, management of a brain tumor depends on many factors, including the person’s age, comorbid conditions, tumor type, tumor grade, and the genetic mutation of the tumor itself. Some genetic mutations can guide treatment options that can even be identified on certain MRIs.
Treatment usually consists of tumor removal with brain surgery, which also provides brain tissue for biopsy. Doctors can then test the cells for different markers to determine further diagnosis and management options. Some tumors are cured by surgery alone while some more aggressive tumors may also need chemotherapy and radiation therapy.
The more aggressive the brain tumor, the more important it is to have an experienced team that might include oncology specialists, neurosurgeons, and neurologists.
There are many types of brain tumors ranging from noncancerous to cancerous, and low grade to high grade. Symptoms can range from headaches to seizures and some people have no symptoms at all. While diagnosis and treatment can seem like a complicated process, early detection of cancer improves prognosis.
Learning about different types of brain tumors can seem scary, but advanced imaging for early detection and medical therapies for treatment bring a brighter outlook. One way to take charge of your own health is to assess your own risk for various cancers, including brain cancer, and screen before symptoms come up.
Knowledge is power. Getting more information about your brain health — and your entire body — is a proactive step for your well-being. With an Ezra MRI, you can get a clear picture of your whole body, which can produce life-changing results. Book an Ezra Full Body Scan to get the information you need without any harmful radiation.