Understanding brain tumors
What are brain tumors?
Although there are more than 120 different kinds of brain tumors, they all have one thing in common — they are the result of abnormal cells that, despite being damaged, are able to multiply instead of dying off.
As these abnormal cells continue to reproduce in or near your brain, they eventually form a physical mass, or tumor. The tumor can disrupt normal brain functions if it has invaded the surrounding brain tissue or is pressing up against delicate nerves, blood vessels or other structures near the brain, including the pituitary or pineal glands.
Types of brain tumors
Some brain tumors are cancerous (these are called malignant tumors) and others are not (these are benign tumors). If a tumor begins in your brain, it is called a primary brain tumor. If it is caused by cancer that started somewhere else in your body and then spread to your brain, it's called a metastatic or secondary brain tumor.
Primary brain tumors are less common than metastatic tumors. Despite this, there are many types of primary brain tumors, each named for the specific kind of cell it grew from. Examples include:
- Gliomas are the most common type of primary brain tumor. This category includes tumors called glioblastomas, astrocytomas, oligodendrogliomas, ependymomas, oligoastrocytomas and gliosarcomas.
- Pituitary tumors develop in or near the pituitary gland, which is located at the base of the brain and is responsible for releasing hormones that help regulate the thyroid, ovaries, testes and other glands. These mostly benign tumors include pituitary adenomas and craniopharyngiomas.
- Meningiomas are tumors that begin in the layers of tissue that surround the brain and spinal cord (called meninges). Meningiomas are typically benign.
- Acoustic neuromas, also known as vestibular schwannomas, are benign, often slow-growing tumors that develop on the main nerve running from the inner ear to the brain.
- Chordomas are cancerous tumors that develop within the bones that make up the skull and spine.
- Medulloblastomas, also known as primitive neuroectodermal tumors or PNETs, are cancerous tumors that form in the back of the brain near the base of the skull. They often spread to other parts of the brain and spinal cord. These tumors occur primarily in children.
- Pineal tumors develop in the pineal gland, which is located within the brain and is responsible for releasing hormones such as melatonin. Pineal tumors include pineocytomas and pineoblastomas.
- Germ cell tumors are a group of malignant and benign tumors that occur in children. Although they typically form in the reproductive cells of the testes and ovaries, they can also develop near the pineal gland inside the brain.
Unlike primary brain tumors, which can be malignant or benign, metastatic brain tumors always are cancerous. Although any kind of cancer can spread to the brain, certain types have a higher probability of doing so. These include:
- breast cancer
- lung cancer
- colon cancer
- melanoma (a type of skin cancer)
- leukemia (a type of blood cancer)
- lymphoma (another type of blood cancer)
What are the symptoms of a brain tumor?
Given the variety and complexity of brain tumors, there is not a single set of symptoms that can be attributed to all of them. Symptoms vary greatly by individual and depend on the size and location of the tumor, as well as how fast it is growing.
General symptoms that people with brain tumors often report include:
- headaches that are new (especially among people who don't normally experience them) or a noticeable difference in headache pattern (among people who already manage headache pain)
- headaches that get worse over time, in both frequency and severity
- nausea or vomiting unrelated to any other illness
- trouble seeing in one or both eyes, including blurred or double vision
- trouble speaking
- trouble hearing
- confusion or trouble understanding
- personality changes
- numbness or weakness in an arm or leg
- clumsiness or balance problems
- new and unexplained seizures
Who is at risk for a brain tumor?
There are few definitive risk factors associated with brain tumors. Although it is clear that metastatic brain tumors are caused by cancer that spread to the brain from somewhere else in the body, in most people with a primary brain tumor there is no known cause.
To date, research has identified only a few risk factors linked to brain tumor development. These include:
- Age – As with many medical conditions, your risk of developing a brain tumor increases with age. Although children and adults of all ages can get brain tumors, they are most common in older adults.
- Exposure to ionizing radiation – People who have been exposed to a certain type of radiation called ionizing radiation have an increased risk of developing a brain tumor. For example, children who receive radiation therapy to treat childhood cancer have a higher risk of developing a brain tumor later in life.
- Family history of brain tumors or certain medical conditions – People who have a family history of brain tumors are at an increased risk of developing that same type of tumor. Additionally, people with a family history of certain diseases (including neurofibromatosis type 1 and 2, tuberous sclerosis, Von Hippel-Lindau disease and Li-Fraumeni syndrome) are more likely to develop brain tumors.
How are brain tumors diagnosed?
If your doctor suspects you have a brain tumor, he or she will perform a combination of some of the following tests to rule out other medical conditions and confirm a diagnosis:
- A neurological exam – Because the brain controls all of your bodily functions, ranging from vision and breathing to muscle control, your doctor may begin by checking your eyes, hearing, balance, reflexes, strength and coordination. If he or she notices anything unusual during the exam, it may help narrow down where in the brain a possible tumor is located.
- Imaging tests – A variety of imaging procedures including magnetic resonance imaging (MRI), computerized tomography (CT) scans and positron emission tomography (PET) scans are used to capture images of the tumor, pinpoint where in the brain it is located and begin treatment planning.
- If your doctor thinks your brain tumor might be metastatic, these same imaging tests can be used to scan other parts of the body to detect where the original cancer is located (for example, in the breast or colon).
- Biopsy – A biopsy is a procedure used to collect a tissue sample for examination under a microscope. It is often used to determine whether a tumor is benign or malignant. Although there are different kinds of biopsies, including needle biopsy and stereotactic biopsy, the procedure generally requires a physician to access the brain using surgical tools, then remove a small piece of tissue from the tumor.
How are brain tumors treated?
If your doctor confirms you have a brain tumor, he or she will create a treatment plan that is based on several factors, including the type of tumor, its size and location, and your overall health.
Your doctor will work closely with other specialists who may be involved in your treatment, such as brain surgeons (neurosurgeons), doctors who oversee radiation treatment (radiation oncologists) and doctors who oversee chemotherapy (medical oncologists).
Your treatment plan may include one or more of the following:
- Surgery may be used to remove a part or all of the tumor if it is located in an area of the brain that is easily accessible. During the procedure, a neurosurgeon first performs a craniotomy to temporarily remove a piece of the skull and gain access to the brain, then uses surgical tools to cut out as much of the brain tumor as possible.
- Radiation therapy is a common treatment for most kinds of cancer, including brain tumors. It uses radiation in several forms, including X-rays, Gamma rays and protons, to damage or destroy tumor cells. Radiation beams can be aimed directly at the tumor or they can be applied to the entire brain (this is called whole-brain radiation). Either way, the goal is to damage as much of the cancer as possible while preserving healthy brain tissue.
- Radiosurgery, or stereotactic radiosurgery, also uses radiation beams to destroy brain tumors (despite what the name implies, it is not surgery in the traditional sense because the procedure does not require cutting or an incision). During the procedure, multiple beams of radiation are simultaneously aimed at the brain. The beams meet at the tumor to deliver a single, massive dose of radiation. Unlike traditional radiation therapy, which is often given in multiple doses over a period of time including weeks or months, radiosurgery often requires only one treatment.
- Chemotherapy uses special cancer-fighting drugs to kill tumor cells. Some people receive chemotherapy by mouth (in pill form) and others receive it intravenously (through a needle placed in a vein). Treatment often occurs over a period of time ranging from weeks to months.
- Targeted drug therapy also uses medication to fight cancerous brain tumors. Unlike chemotherapy, which exposes the entire body (including healthy cells) to powerful cancer-fighting drugs, newer targeted drugs interfere primarily with the abnormal cells that make up tumors. For example, some drugs block blood vessel formation, which can kill a tumor by cutting off its blood supply. Others can block enzymes that help cancer cells grow.
During or after treatment, your doctor may recommend additional services to help address any impairments caused by the tumor. For example, if the tumor affected your vision, speech, muscle control, memory or thinking, you may benefit from rehabilitation services including physical, occupational or speech therapy.
Brain tumor surgery at Lyerly Neurosurgery
Since Lyerly Neurosurgery was founded in 1934, our physicians have cared for thousands of people who need treatment for a brain or spine condition.
Today our practice continues to build upon a legacy that blends compassion, safety and innovation. In partnership with Baptist Medical Center Jacksonville, our physicians routinely collaborate with cancer specialists who have referred their brain tumor patients to us for surgery.
Our team has the advanced training and experience necessary to treat even the most rare or complex brain tumors, and includes physicians who are fellowship trained in surgical neuro-oncology and specialize in the latest minimally invasive cranial techniques.