Malignant central nervous system neoplasms represent a complex group of cancerous tumors that develop in the brain or spinal cord, affecting thousands of adults and children each year. These aggressive growths challenge patients and their families with difficult journeys through diagnosis, treatment, and recovery, yet advances in medical science continue to offer new hope and improved outcomes for those facing these serious conditions.
Understanding Central Nervous System Tumors
A malignant central nervous system neoplasm is a cancerous tumor that forms when abnormal cells grow uncontrollably in the tissues of the brain or spinal cord. Together, the brain and spinal cord make up the central nervous system, which controls nearly every function of the body. These tumors are different from benign tumors because they grow quickly and can spread into nearby healthy brain tissue. When a tumor grows into or presses on an area of the brain, it may stop that part of the brain from working properly.[1]
There are many different types of these tumors, formed by abnormal growth of cells that may begin in different parts of the brain or spinal cord. Some tumors start directly in the brain and are called primary brain tumors. Others begin somewhere else in the body and spread to the brain, and these are called metastatic brain tumors. Primary brain tumors may spread to other parts of the brain or spine, but they rarely spread to other parts of the body.[1]
Brain tumors account for the vast majority of all primary central nervous system tumors, making up between 85% and 90% of all cases. The tumors may be either benign, meaning they are not cancerous, or malignant, meaning cancer is present. However, both benign and malignant brain tumors cause symptoms and need treatment because even non-cancerous tumors can press on vital brain structures.[1][12]
Approximately 78% of cancerous primary brain tumors are gliomas, which develop in glial cells that surround and support nerve cells. Other common types include meningiomas, pituitary tumors, schwannomas, ependymomas, and medulloblastomas. Each type behaves differently and requires specific treatment approaches.[4]
How Common Are These Tumors
In the United States, an estimated 24,820 new cases of brain tumors and other nervous system tumors are expected to be diagnosed in 2025, with approximately 18,330 deaths from these conditions. These numbers show that while these tumors are serious, they represent a relatively uncommon group of cancers compared to other cancer types.[12]
Data from recent years show that the combined incidence of brain and other central nervous system tumors in the United States is about 6.2 cases per 100,000 people per year. The mortality rate is 4.4 deaths per 100,000 people per year. Worldwide, approximately 321,476 new cases were diagnosed in 2022, with an estimated 248,305 deaths.[12]
The incidence of primary central nervous system tumors is generally higher in white individuals than in black individuals, and mortality is higher in men than in women. Central nervous system tumors are the second most common childhood tumor type, with around 4,000 new cases diagnosed in children each year in the United States.[2][12]
Brain tumors can occur in both adults and children, though treatment for children may be different than treatment for adults. The risk of developing a central nervous system tumor generally increases with age, making these tumors more common in older adults. However, certain types of tumors, such as medulloblastomas, appear more frequently in children and young adults.[1]
Up to half of metastatic brain tumors come from lung cancer. Often, tumors found in the brain have started somewhere else in the body and spread to one or more parts of the brain. Metastatic brain tumors are actually more common than primary brain tumors.[1]
What Causes Central Nervous System Tumors
The cause of most adult brain and spinal cord tumors is not known. Researchers believe that something goes wrong during the normal development of cells in the brain or spinal cord. These cells undergo changes in their DNA, resulting in abnormal growth and the development of a primary brain tumor.[1][2]
Few definitive observations have been made about environmental or occupational causes of primary central nervous system tumors. However, exposure to vinyl chloride may be a risk factor for glioma. This is one of the few environmental connections that researchers have identified.[12]
Certain viral infections have been linked to these tumors. Epstein-Barr virus infection has been implicated in the development of primary central nervous system lymphoma. People who have received organ transplants and patients with AIDS have a substantially increased risk of developing primary central nervous system lymphoma.[12]
Cancers that spread to the brain from other organs are called metastatic tumors. These most commonly come from lung cancer, but can also originate from cancers of the kidneys, breasts, and other organs. Cancer may also spread to the leptomeninges, which are the two innermost membranes covering the brain and spinal cord. This is called leptomeningeal carcinomatosis.[1]
Who Is at Higher Risk
Having certain genetic syndromes may increase the risk of developing a central nervous system tumor. Several familial tumor syndromes and related chromosomal abnormalities are associated with central nervous system neoplasms. These inherited conditions can be passed down from parents to their children.[1]
Some genetic conditions that researchers have found can give a person a higher risk of developing these tumors include neurofibromatosis type 1 and type 2, von Hippel-Lindau disease, tuberous sclerosis, Li-Fraumeni syndrome, Turcot syndrome, and nevoid basal cell carcinoma syndrome. People with these conditions should be monitored more closely for signs of tumor development.[12]
Age is an important risk factor. In general, the risk of developing a central nervous system tumor increases as people get older. These tumors are more common in older adults, though specific types can occur at any age. For example, glioblastomas appear more often in older adults, while medulloblastomas are more common in children.[5]
Previous radiation exposure is another recognized risk factor. People who have undergone radiation therapy to the head may have an increased risk of developing a brain tumor later in life. This connection has been established through research on patients who received radiation treatment for other conditions.[9]
A family history of central nervous system tumors or certain other cancers can increase risk, particularly when inherited genetic syndromes are present. However, most people who develop brain tumors do not have a family history of the disease. Additionally, people with weakened immune systems, such as those with HIV or organ transplant recipients, face a higher risk of certain types of brain tumors, particularly primary central nervous system lymphoma.[9][12]
Common Signs and Symptoms
The signs and symptoms of adult brain and spinal cord tumors are not the same in every person. Symptoms vary depending on where the tumor is located in the brain or spinal cord, how large it is, and how quickly it grows. If a brain tumor starts in a part of the brain that is less active, it might not cause symptoms right away and could become quite large before being discovered.[1][3]
Headaches are among the most common symptoms. These headaches may be severe and persistent, often worse in the morning or after vomiting. Many people with brain tumors experience headaches that are different from their usual headaches in pattern or intensity. However, it is important to remember that most headaches are not caused by brain tumors.[7][9]
Seizures are another frequent symptom, occurring in many people with brain tumors. These may be the first sign that something is wrong, especially in people who have never had seizures before. Changes in vision are also common and may include blurry vision, double vision, or loss of vision in one or both eyes. These vision changes depend on where the tumor is located.[1][9]
Nausea and vomiting, particularly in the morning, can occur with brain tumors. This happens because increased pressure inside the skull affects the brain’s normal function. Loss of appetite and unintended weight loss may also develop. Some people experience weakness or numbness in parts of the body, often on one side, or have trouble with balance and coordination. Dizziness or vertigo can make it difficult to walk or perform daily activities.[7][9]
Changes in personality, mood, or behavior may be noticed by family members or friends. Memory problems, difficulty concentrating, or confusion can develop. Some people have trouble speaking or understanding others. These cognitive and emotional changes occur because the tumor affects areas of the brain responsible for these functions.[1][9]
For tumors located in the spinal cord, symptoms usually start with back pain that spreads toward the arms or legs. These tumors can cause trouble urinating or walking. The specific symptoms depend greatly on which part of the spinal cord is affected by the tumor.[9]
In pediatric patients, symptoms may also include abnormal head position, delayed puberty, abnormal growth, excessive thirst, reduced consciousness, and behavioral changes. Young children may not be able to describe their symptoms clearly, so caregivers need to watch for changes in behavior or development.[9]
Prevention Strategies
Because the cause of most central nervous system tumors is unknown, there are no proven ways to prevent them. Unlike some other types of cancer, there are no lifestyle changes or behaviors that have been shown to significantly reduce the risk of developing these tumors. Most people who develop brain tumors have no identifiable risk factors that could have been modified or avoided.[1]
For people with known genetic syndromes that increase their risk, regular monitoring and surveillance may help detect tumors at earlier stages when they may be more treatable. Families with a history of inherited conditions associated with brain tumors should consider genetic counseling to understand their risk and surveillance options.[12]
Avoiding unnecessary radiation exposure to the head is one of the few preventive measures that may reduce risk. This means medical imaging tests involving radiation should only be performed when medically necessary. However, when imaging is needed for diagnosis or treatment of other conditions, the benefits typically outweigh the small increased risk of future tumor development.[9]
Maintaining overall good health through a balanced diet, regular exercise, adequate sleep, and stress management supports the immune system and general wellbeing. While these healthy habits have not been proven to prevent brain tumors specifically, they contribute to better health outcomes overall and may help the body cope better if a tumor does develop.[9]
How Tumors Affect the Body
The brain controls many important body functions through its different parts. The cerebrum, which is the largest part of the brain located at the top of the head, controls thought, learning, and the senses. When a tumor grows into or presses on an area of the brain, it may stop that part from working the way it should. This explains why both benign and malignant brain tumors cause symptoms and need treatment.[1]
Malignant brain and spinal cord tumors are likely to grow quickly and spread into other brain tissue. Unlike benign tumors that grow slowly and stay in one place, cancerous tumors invade surrounding healthy tissue. This invasion disrupts normal brain function in the affected areas. As the tumor grows, it creates pressure on and changes the function of surrounding brain tissue, causing the various signs and symptoms that patients experience.[1][3]
Different locations of tumors in the brain cause different problems. Tumors in the cerebrum, which controls movement, may cause weakness or numbness to the body, often limited to one side. Tumors in areas that control speech can cause difficulty speaking or understanding words. Those in areas controlling movement may cause problems walking or using arms, hands, fingers, and legs. Tumors near the visual centers can cause blurred vision, double vision, or loss of vision.[9]
The pressure that builds up inside the skull as a tumor grows contributes to many symptoms. This increased intracranial pressure can cause headaches, nausea, vomiting, and changes in consciousness. The tumor may also block the flow of cerebrospinal fluid, which normally cushions the brain and spinal cord, leading to a buildup of fluid and further pressure increase.[3]
Tumors can damage brain tissue directly through their growth and invasion, or indirectly by pressing on nearby structures. They may also cause swelling in surrounding brain tissue, further compromising function. Some tumors affect blood flow to parts of the brain or damage the blood-brain barrier, which normally protects the brain from harmful substances in the bloodstream.[3]
Primary brain tumors rarely spread to other areas of the body outside the central nervous system, but they can spread to other parts of the brain and to the spinal axis. This pattern of spread differs from many other cancers, which commonly metastasize to distant organs. However, when cancer from other parts of the body spreads to the brain, it demonstrates how these tumors can disrupt the central nervous system’s carefully coordinated functions.[12]
