Malignant Central Nervous System Neoplasm

A malignant central nervous system neoplasm is a cancerous tumor that develops in the brain or spinal cord. These tumors grow quickly and can spread into surrounding tissue, causing serious health problems that require immediate medical attention.

Table of contents

• What Is a Malignant Central Nervous System Neoplasm
• Types of Malignant CNS Tumors
• Causes and Risk Factors
• Signs and Symptoms
• Diagnosis
• Treatment Options
• Outlook and Survival
• Living with a CNS Tumor

What Is a Malignant Central Nervous System Neoplasm

A malignant central nervous system neoplasm is a disease in which abnormal cells form in the tissues of the brain or spinal cord^[1]. Together, the brain and spinal cord make up the central nervous system (CNS), which controls many important body functions^[1].

These tumors are malignant, meaning they are cancerous. Malignant brain and spinal cord tumors grow quickly and are likely to spread into other brain tissue^[1]. When a tumor grows into or presses on an area of the brain, it may stop that part of the brain from working the way it should^[1].

Tumors that start in the brain or spinal cord are called primary brain tumors^[1]. Primary brain tumors may spread to other parts of the brain or to the spine, but they rarely spread to other parts of the body^[1]. It is important to distinguish these from metastatic brain tumors, which start in another part of the body and spread to the brain^[1].

Brain tumors account for 85% to 90% of all primary central nervous system tumors^[12]. In the United States, the combined rate of brain and other CNS tumors was 6.2 cases per 100,000 people per year based on data from 2017 to 2021^[13].

• Brain
• Spinal cord

Types of Malignant CNS Tumors

There are many different types of malignant brain and spinal cord tumors. Approximately 78% of cancerous primary brain tumors are gliomas, which develop in glial cells that surround and assist nerve cells^[4].

The most common types of malignant CNS tumors include:

• Glioblastoma and anaplastic astrocytomas make up 38% of primary brain tumors. These are aggressive tumors that form in star-shaped glial cells called astrocytes^[13].
• Astrocytomas can form in many parts of the brain, but most commonly occur in the cerebrum^[4].
• Ependymomas often occur near the ventricles in the brain and develop from ependymal cells^[4].
• Oligodendrogliomas form from oligodendrocytes, which are cells that make the protective covering around nerve cells^[1].
• Medulloblastomas are fast-growing tumors that form at the base of the skull^[1].

For primary spinal tumors, the most common types include schwannomas, meningiomas, and ependymomas, which together account for 79% of primary spinal tumors^[13].

Central nervous system tumors can occur in both adults and children. Around 4,000 new cases of CNS tumors are diagnosed in children each year in the United States^[2].

Causes and Risk Factors

The cause of most adult brain and spinal cord tumors is not known^[1]. Few definitive observations have been made about environmental or occupational causes of primary CNS tumors^[13].

Having certain genetic syndromes may increase the risk of a CNS tumor^[1]. The following familial tumor syndromes and related chromosomal abnormalities are associated with CNS tumors^[13]:

• Neurofibromatosis type 1
• Neurofibromatosis type 2
• von Hippel-Lindau disease
• Tuberous sclerosis
• Li-Fraumeni syndrome
• Turcot syndrome
• Nevoid basal cell carcinoma syndrome

Some research has found that exposure to vinyl chloride may be a risk factor for glioma^[12]. Epstein-Barr virus infection has been implicated in the development of primary CNS lymphoma^[12]. Transplant recipients and patients with AIDS have a substantially increased risk of primary CNS lymphoma^[12].

In most cases for children with CNS tumors, there is no known cause. Researchers believe that something is absent in the brain or spinal cord cells during normal development^[2].

Signs and Symptoms

The signs and symptoms of adult brain and spinal cord tumors are not the same in every person^[1]. Symptoms vary depending on the tumor’s location, size, and how quickly the tumor grows^[3].

Common symptoms of CNS tumors include^[9]:

• Headaches, which may be more severe in the morning
• Seizures or convulsions
• Nausea and vomiting
• Vision, hearing, and speech problems
• Loss of appetite
• Changes in personality, mood, ability to focus, or behavior
• Weakness or numbness in parts of the body
• Difficulty with balance or coordination
• Dizziness
• Memory problems

In children, symptoms may also include unsteady gait, slowed speech, abnormal head position, delayed puberty, abnormal growth, excessive thirst, and reduced consciousness^[9].

For spinal cord tumors, symptoms usually start with back pain that spreads towards the arms or legs. These tumors can cause trouble urinating or walking^[9].

Diagnosis

Tests that examine the brain and spinal cord are used to diagnose adult brain and spinal cord tumors^[1]. A biopsy is also used to diagnose a brain tumor^[1].

If a healthcare professional thinks you might have a brain tumor, you’ll need a number of tests and procedures to get a diagnosis^[17]. These might include:

Neurological exam: A neurological exam tests different parts of the brain to see how they’re working. This exam may include checking vision, hearing, balance, coordination, strength and reflexes^[17].

Imaging tests: Several imaging techniques help diagnose brain tumors:

• Computed tomography (CT) scan uses X-rays to make pictures. It’s widely available, and results come back quickly^[17].
• Magnetic resonance imaging (MRI) uses strong magnets to create pictures of the inside of the body. MRI is often used to detect brain tumors because it shows the brain more clearly than other imaging tests^[17]. Often a dye is injected into a vein in the arm before an MRI to make certain details more clear^[17].

Biopsy: A biopsy helps the doctor diagnose a medical condition. During a biopsy, a sample of tissue is removed and examined under a microscope^[1]. Sometimes a biopsy or surgery cannot be done^[1].

Treatment Options

Both benign and malignant brain tumors cause signs and symptoms and need treatment^[1]. The two most effective treatments for CNS tumors are radiation therapy and surgery, though some cancers also respond well to chemotherapy, especially those that occur in children^[10].

Surgery: Surgery is particularly effective in less aggressive tumors, and often is curative without further therapy^[10]. However, many areas of the brain cannot be operated on, making definitive surgery impossible, and there are even a few areas that cannot be biopsied^[10]. With surgery, the main goal is to remove as much of the tumor as possible while retaining brain function^[28].

Radiation therapy: Because many areas of the brain cannot be operated on, radiation therapy is required for virtually every malignant tumor of the central nervous system^[10]. Radiation therapy uses high-energy beams to destroy cancer cells in malignant tumors or slow down noncancerous tumor growth^[21].

Chemotherapy: Chemotherapy uses drugs to kill cancer cells or stop them from growing. Some brain tumors respond well to chemotherapy^[1].

Treatment for children with CNS tumors may be different than treatment for adults^[1].

Outlook and Survival

Certain factors affect prognosis (chance of recovery) and treatment options^[1]. The cure rate for primary brain tumors varies dramatically with the type of tumor and the site of origin in the brain^[10].

Survival is most impacted by whether the tumor is malignant or benign, and how much of the tumor can be removed through surgery^[28]. When it comes to benign tumors, if the whole tumor is removed during surgery, a patient likely will have a positive outcome^[28]. However, even if a malignant tumor is completely removed, it might come back^[28].

For some of the childhood tumors, such as medulloblastoma, identification of risk types and improved treatment have resulted in longer quality-adjusted survival^[5]. However, for the most malignant glioma, glioblastoma multiforme, older adults with this disease rarely live longer than one year^[5].

Age is an important predictor of survival, as is the patient’s level of neurological functioning at the time they start treatment^[5].

Living with a CNS Tumor

Living with a central nervous system tumor can impact all aspects of life. This can be challenging for patients and their loved ones^[22].

A brain tumor diagnosis is a life-altering event. There is no “right” way to feel. There will probably be days when people feel upbeat and positive and other days when they will feel that their world has caved in^[20]. Uncertainty is among the most challenging aspects of a brain tumor diagnosis^[20].

Many people who live with a brain tumor or who are recovering from brain tumor treatment experience significant changes in the way they function^[20]. Brain tumors can create problems with vision, weakness on one side of the body, and cognitive changes^[27].

Making the transition from battling cancer to dealing with everyday life can be very challenging for brain cancer survivors. Cognitive loss resulting from surgery can affect work and daily activities^[27]. However, with the best possible treatment and support, it is possible to find a way to accept life’s changes and focus energy on adjusting to this new reality^[20].

Having a strong support system is very important. Family, friends, and healthcare providers can provide essential support during treatment and recovery^[23].