Brain tumors may be “primary” such that they arise from the brain itself, its covering (called the meninges), or nerves—or they can be “metastatic,” meaning a cancer arising elsewhere in the body has spread to the brain. They can also be more “benign,” or slow-growing, versus more malignant and aggressive. While some hereditary syndromes can predispose people to develop brain tumors, such as Neurofibromatosis Syndrome (NF) 1 or 2, the vast majority of brain tumors are sporadic—or occur randomly and by chance.
The Chênevert Family Brain Tumor Center is one of the leading centers in the world for the management of all types of brain tumors. The multidisciplinary team of highly experienced and specialized brain tumor experts, including neurosurgeons, neuro-oncologists, radiation oncologists, neuropathologists, neuroradiologists, and neurogeneticists, offers patients with brain tumors state-of-the-art care.
“At Yale, we appreciate how scary the diagnosis of a brain tumor can be. We are committed and able to help all patients with all types of brain tumors,” says Yale Medicine neurosurgeon and brain tumor specialist, Jennifer Moliterno, MD.
What are the types of brain tumors?
Primary brain tumors. Primary brain tumors are usually classified based on the type of cell from which they arise and their location in the brain.
Most can be subdivided based on their molecular features, or the mutations that cause the tumor to form and grow. Brain tumors can be further categorized according to a grading system, ranging from Grade I (most benign) to Grade IV (most malignant or aggressive).
Malignancy or aggressiveness means the tumor has the highest chance of recurring or coming back after treatment. Primary brain tumors rarely, if ever, metastasize outside of the brain. If and when they recur, they typically do so locally in the brain.
Below are examples of primary brain tumors.
- Meningiomas—tumors that arise from the meninges (the membranes that cover the brain and spinal cord)—are the most common. These tend to be slow-growing, with the majority being more benign compared with other types of tumors. However, meningiomas can lead to compression of areas of the brain and nerves, and surround blood vessels, all of which can cause problems for patients. The typical treatment involves surgery and, at times, radiation.
- Gliomas: Tumors that arise from the brain itself, and include the subtypes astrocytomas, oligodendrogliomas, and ependymomas, depending on the exact cell type from which they arise. The most aggressive form of astrocytoma, known as glioblastomas, can be difficult to treat. Surgical removal of cancerous tissue, typically followed by radiation and chemotherapy, and/or enrollment in clinical trials (more information is below) is an important treatment strategy for these tumors. They can occur in what’s called the “eloquent brain,” which refers to areas of the brain that control important neurologic functions. Two such areas are the motor cortex and language cortex, which control motor skills and language processing, respectively.
- Schwannomas are tumors that start in nerve cells known as Schwann cells, most commonly along a cranial nerve known as the vestibulocochlear nerve. This nerve sends information about head position, balance, and sound to the brain. Tumors that affect this nerve are known as vestibular schwannomas or acoustic neuromas. They are typically benign but can significantly impair patients, from a quality of life perspective.
- Medulloblastomas are tumors that arise from neuroectodermal cells in the cerebellum, a part of the brain responsible for coordinating muscle movement and balance. All medulloblastomas are aggressive and more commonly affect children than adults.
- Gangliogliomas are tumors that are made up of glial cells and ganglion cells. These rare tumors are usually slow-growing.
- Pituitary gland tumors begin in the pituitary gland, a gland located at the base of the brain. They are usually benign but can grow large enough to press against brain structures and nerves—especially the optic nerves—and can cause various symptoms.
- Craniopharyngiomas are slow-growing tumors that form near the pituitary gland and hypothalamus (a region of the brain located near the pituitary). Although they are more common in children, they often occur in adults.
- Primary central nervous system lymphomas begin in the lymph cells in the brain.
- Pineal gland tumors develop in the pineal gland, a small gland near the center of the brain. Cysts are much more common than tumors in this location, and there is a spectrum of malignancy with regards to the tumor types.
Other types of primary tumors can occur, such as central neurocytoma and subependymoma.
Metastatic brain cancers. These are cancers that arise from other organs in the body that have spread to the brain. Brain metastases most commonly occur in people with lung and breast cancers, though other types of cancer, such as melanoma and renal cell cancer, may also spread to the brain.
What are the symptoms of brain tumors?
Symptoms can vary widely depending on the part of the brain that’s involved. Some patients have no symptoms at all. But, for those who do, symptoms may include, but are not limited to:
- Nausea and vomiting
- Vision or hearing problems
- Changes in personality, behavior, or mood
- Changes in speech or language
- Difficulty with walking or movement
- Numbness or tingling
Children may experience some additional symptoms that may include:
- Enlarged head (in babies)
- Developmental delays
- Loss of appetite
- Ongoing irritability
- Diminished learning ability
How are brain tumors diagnosed?
Doctors can perform a series of tests to diagnose suspected brain tumors.
Often, a physical exam with a focused neurological evaluation that includes simple tests—like assessments of motor skills and senses—may help identify the part of the brain or nervous system that’s involved.
Next, diagnostic imaging studies (most commonly MRI or CT scan) are often obtained to better understand whether a tumor exists, and if it does, to evaluate its location, size, and effect on surrounding tissue.
Ultimately, a brain tumor neurosurgeon can obtain a sample of the tumor, if necessary. Because not all brain tumors need to be sampled, a neurosurgeon’s expertise is important in determining this step.
At Yale, after a sample of tumor is obtained, highly specialized neuropathologists will study the tumor tissue under a microscope to determine whether it is malignant or benign, as well as the tumor type. A genomic analysis of the tumor tissue is then performed to further understand the make-up of mutations in the tumor. The expertise and experience of the treating physicians and team are important as each step is critical in ensuring the success of making the diagnosis and managing the brain tumor appropriately.
How is a brain tumor treated?
Not all brain tumors require treatment. As a general rule, brain tumor treatment is recommended if a patient has symptoms from the tumor, and/or the tumor is relatively large in size with or without associated changes in the brain. (These changes can include swelling or what’s called “mass effect,” which occurs when tumors grow and press against surrounding brain tissue and structures). Treatment is also recommended if the tumor is concerning because it is a more aggressive tumor type.
For those tumors that do not require treatment, surveillance imaging or periodic MRIs allow physicians to follow the tumor’s behavior and growth, and intervene when—and if—necessary.
- Surgery. Surgery is often the first line of treatment for brain tumors. The goal for most primary brain tumors is to remove as much of the tumor as safely as possible while preserving, or even improving, brain function. At Yale, neurosurgeons use highly sophisticated microsurgical techniques and, at times, can keep patients awake and comfortable during surgery to ensure all of the tumor is removed while preserving language or strength.
Chemotherapy. These drugs are typically used following surgery for more aggressive, malignant brain tumors, and are usually used in combination with radiation as part of the “standard of care.” They work to further destroy or damage microscopic cancer cells, with the goal of preventing recurrence or regrowth.
- Radiation therapy. Various types of radiation can also be used to target and treat brain tumors, depending on the number, size, location, and type of brain tumor involved. Stereotactic radiosurgery (SRS), for instance, precisely delivers a large dose of radiation only to the tumor, minimizing any exposure to the surrounding brain—and typically in one treatment session. Gamma Knife radiosurgery is an example of SRS and is used most commonly for metastatic tumors, as well as in limited use for some primary brain tumors.
- Clinical trials and other treatment therapies. Clinical trials, offering treatments that are novel and on the cutting edge, offer hope for challenging brain tumors. Targeted therapy, such as immunotherapy, can be used to treat brain tumors and is often guided in a precision-medicine approach based on genomic analysis. Some tumors can also be treated with alternating electric field therapy.
- Other drugs, such as corticosteroids and anti-seizure drugs, are commonly used to reduce swelling and seizure risk, respectively.
What stands out about Yale Medicine's approach to patient care?
The Chênevert Family Brain Tumor Center is proud to care for the most number of brain tumor patients each year in Connecticut. This is largely due to the exceptional outcomes afforded by the collaborative work of a team of specialists who are dedicated to the care of patients with all types of brain tumors.
The Center offers unparalleled experience, knowledge, and the compassion necessary for the diagnosis and treatment of any type of brain tumor. Moreover, they are readily available, understanding the urgency of a brain tumor, and routinely see patients within 24 hours of referral. Newly diagnosed patients, as well as those with more complex recurrent tumors, are accepted, and second or third opinions are offered. The team at the Chênevert Family Brain Tumor Center recognizes how overwhelming any brain tumor diagnosis can be, and provides the best possible care with the utmost compassion and support.
“Our care for brain tumor patients is truly unsurpassed and why we are the Center patients and physicians always turn to for the most cutting-edge, compassionate brain tumor care,” says Dr. Moliterno. “It is an honor to be entrusted by the most number of brain tumor patients each year in Connecticut.”