Malignant ependymoma is a rare type of brain or spinal cord tumor that grows quickly and requires careful medical attention. It develops from special cells that line the fluid-filled spaces in the central nervous system, and while it can affect anyone, it most commonly appears in children and young adults. Understanding this condition helps patients and families navigate the journey ahead with greater confidence and clarity.

What is Malignant Ependymoma?

Malignant ependymoma is a cancerous tumor that forms in the brain or spinal cord. These tumors arise from ependymal cells, which are specialized cells that line the ventricles (fluid-filled chambers) in the brain and the central canal of the spinal cord. These cells normally help produce and manage cerebrospinal fluid, the protective liquid that cushions the brain and spinal cord.^[1]

When ependymal cells begin to multiply uncontrollably, they can form tumors. Healthcare providers classify ependymomas into grades based on how the cells look under a microscope and how quickly they grow. Grade 3 ependymomas, also called anaplastic ependymomas, are considered malignant because they grow rapidly and behave more aggressively than lower-grade tumors.^[2]

Unlike many cancers, malignant ependymomas rarely spread outside the central nervous system to other parts of the body. However, they can spread to other areas within the brain or spinal cord through the cerebrospinal fluid that flows through these spaces.^[2] This ability to move within the central nervous system makes them particularly challenging to treat completely.

The behavior of an ependymoma depends not just on its grade but also on its location and specific genetic features. Recent research has identified different molecular subtypes of ependymoma, which means that tumors that look similar under a microscope may actually behave quite differently based on their genetic makeup.^[2] This discovery has helped doctors better understand why some patients respond differently to treatment than others.

How Common is Malignant Ependymoma?

Malignant ependymoma is quite rare. According to data from the United States, ependymal tumors represent only about 1.7% of all brain and central nervous system tumors. The typical age at diagnosis is around 44 years, though these tumors can develop at any age.^[10]

These tumors affect children more frequently than adults. In fact, ependymoma is the third most common brain tumor in children, with approximately 230 children diagnosed each year in the United States. The condition is diagnosed most often in children aged 8 and younger.^[4] For children and adolescents, ependymomas account for less than 6% of central nervous system tumors.^[7]

In adults, about 1,100 new cases of ependymoma are diagnosed annually in the United States, representing less than 2% of central nervous system tumors in this age group.^[7] The pattern of where these tumors appear differs between age groups. In children, most ependymomas develop in the brain, particularly in the lower back part of the brain called the posterior fossa. By contrast, the majority of ependymomas diagnosed in adults occur in the spinal cord.^[4]

Among all ependymomas, the high-grade, malignant types are the most common. Grade 3 ependymomas occur most often in the brain but can also appear in the spine. They tend to recur after treatment more frequently than lower-grade tumors, which presents ongoing challenges for long-term management.^[2]

What Causes Malignant Ependymoma?

The exact cause of malignant ependymoma remains unknown. Scientists understand that cancer is fundamentally a genetic disease, meaning it results from changes to genes that control how cells function. In the case of ependymomas, certain genetic mutations can lead to increased growth and spread of cancer cells, but what triggers these mutations in the first place is not clearly understood.^[2]

Most cases of ependymoma occur sporadically, which means they appear randomly without any identifiable cause or pattern. Unlike some other cancers, there are no known environmental exposures or lifestyle factors that have been definitively linked to the development of ependymomas.^[4]

Researchers have discovered that ependymomas arising from different regions of the central nervous system are associated with distinct genetic abnormalities. Even though these tumors may look similar when examined under a microscope, they can have very different molecular characteristics. This suggests that ependymomas are not a single disease but rather a collection of different tumor types that happen to originate from the same kind of cell.^[10]

What scientists do know is that the tumor develops when ependymal cells or certain related support cells called glial cells begin to grow out of control. These are cells that normally help maintain the health and function of the nervous system, but something causes them to lose their normal controls on cell division and growth.^[9]

Risk Factors for Developing Malignant Ependymoma

Because the causes of ependymoma are not well understood, researchers have limited information about what circumstances might increase a person’s risk of developing this tumor. However, certain inherited genetic conditions have been associated with a higher likelihood of developing ependymomas.^[4]

The most notable genetic condition linked to ependymoma is neurofibromatosis type 2 (NF2). People who have this inherited disorder, which affects the nervous system, appear to have an increased risk of developing ependymomas. However, even among individuals with NF2, ependymomas remain relatively uncommon, and researchers cannot yet say with certainty that NF2 directly causes these tumors.^[3]

Other rare genetic syndromes have also been mentioned in connection with ependymoma risk. These include Turcot syndrome, BMEN1 syndrome, and certain other hereditary conditions that affect multiple body systems. However, the connections between these conditions and ependymoma are still being studied.^[4]

It is important to note that the vast majority of people diagnosed with ependymoma have no known genetic syndrome or family history of the disease. The tumor appears randomly, affecting otherwise healthy individuals. This makes it very difficult to predict who might develop an ependymoma or to take preventive measures.^[7]

Symptoms of Malignant Ependymoma

The symptoms caused by a malignant ependymoma depend largely on where the tumor is located and how large it has grown. Because these tumors can develop anywhere in the central nervous system, the range of possible symptoms is quite broad. The tumor causes problems either by pressing on nearby structures or by blocking the normal flow of cerebrospinal fluid.^[1]

When a malignant ependymoma develops in the brain, patients commonly experience persistent headaches. These headaches result from increased pressure inside the skull, which can occur when the tumor blocks the flow of cerebrospinal fluid or simply takes up space within the confined area of the skull. Patients may also feel confused or irritable, especially as the pressure builds.^[1]

Nausea and vomiting are frequent complaints, particularly in the morning or when the person changes position. These symptoms, like headaches, often result from increased pressure within the skull. Some patients experience blurry vision or other changes in their eyesight. In more serious cases, seizures can occur when the tumor irritates the brain tissue.^[2]

Children with brain ependymomas may show different signs than adults. Babies and very young children cannot tell their parents what they are feeling, so caregivers must watch for other clues. These might include a head that appears larger than normal, unusual sleeplessness, excessive crying or fussiness that seems out of character, or vomiting and spitting up more than usual.^[3]

When an ependymoma forms in the spinal cord, the symptoms are quite different. Back pain is a common first symptom, though many things can cause back pain, which sometimes leads to delays in diagnosis. As the tumor grows, it can compress the nerves in the spinal cord, leading to numbness, tingling, or weakness in the arms or legs. The specific pattern of symptoms depends on where along the spine the tumor is located.^[1]

Patients with spinal ependymomas may notice they have trouble controlling their bladder or bowels. They might experience difficulty walking or maintaining balance. Some describe a feeling of heaviness or unusual sensations in their trunk, arms, or legs. In some cases, neck stiffness or neck weakness becomes noticeable, particularly if the tumor is located in the upper portion of the spinal cord.^[4]

The symptoms of ependymoma usually develop gradually as the tumor grows. However, because these symptoms can be caused by many other, more common conditions, people sometimes wait weeks or months before seeking medical attention. This is why it is important to see a healthcare provider if symptoms persist or worsen over time.^[2]

Prevention of Malignant Ependymoma

Unfortunately, there are no known ways to prevent malignant ependymoma. Because researchers have not identified clear environmental or lifestyle risk factors that contribute to the development of these tumors, there are no specific actions people can take to reduce their risk.^[7]

Unlike some cancers that can be linked to smoking, sun exposure, diet, or other modifiable factors, ependymomas appear to arise without any known preventable cause. The genetic changes that lead to ependymoma happen randomly in most cases, and scientists have not yet discovered ways to stop these changes from occurring.^[4]

For individuals with known genetic syndromes like neurofibromatosis type 2, regular monitoring by healthcare providers may help detect tumors earlier if they do develop. However, even this surveillance does not prevent the tumor from forming in the first place; it simply allows for earlier detection, which may improve treatment outcomes.^[2]

The best approach for everyone is to be aware of unusual or persistent symptoms, particularly those affecting the nervous system. Seeking prompt medical attention when symptoms arise allows for earlier diagnosis and treatment, which can significantly impact the course of the disease. While this is not prevention in the traditional sense, early detection remains one of the most important factors in achieving better outcomes.^[1]

How Malignant Ependymoma Affects the Body

Understanding how malignant ependymoma affects the body requires looking at what happens when abnormal cells grow in the central nervous system. The brain and spinal cord are responsible for controlling virtually every function in the body, from breathing and heart rate to movement, sensation, and thought. When a tumor develops in these areas, it can disrupt these critical functions in several ways.^[6]

First, the tumor itself takes up physical space. The brain sits within the rigid skull, and the spinal cord runs through the bony spinal column. These are confined spaces with no room for expansion. As an ependymoma grows, it compresses and pushes against surrounding brain or spinal cord tissue. This pressure interferes with the normal function of that tissue, causing symptoms related to whatever part of the nervous system is being compressed.^[15]

Second, ependymomas often form near or within the ventricles of the brain, the chambers through which cerebrospinal fluid flows. When a tumor blocks one of these pathways, cerebrospinal fluid can build up behind the blockage. This condition, called hydrocephalus, creates dangerous pressure throughout the brain. The increased pressure can cause headaches, vision problems, and other neurological symptoms. In severe cases, it can be life-threatening if not treated promptly.^[4]

In the spinal cord, a growing ependymoma compresses the nerve fibers that carry signals between the brain and the rest of the body. These nerve pathways control movement, sensation, and various automatic functions. When they are compressed or damaged, the parts of the body below the level of the tumor can be affected. This explains why someone with a spinal cord ependymoma might experience weakness in the legs or problems with bladder control.^[2]

Malignant ependymomas are considered cancerous because they grow more aggressively than lower-grade ependymomas. The cells divide rapidly and can infiltrate nearby brain or spinal cord tissue. While they rarely spread outside the central nervous system to other organs like the lungs or bones, they can spread within the central nervous system itself. Cancer cells can break away from the main tumor and travel through the cerebrospinal fluid to other areas of the brain or spinal cord, where they can form new tumors.^[2]

The body’s normal defense mechanisms have limited ability to fight these tumors. The immune system, which usually helps protect against abnormal cells, has restricted access to the brain and spinal cord because of a protective barrier called the blood-brain barrier. This barrier normally prevents harmful substances from entering brain tissue, but it also limits the immune system’s ability to attack tumor cells in these areas.^[10]

Treatment itself can also affect how the body functions. Surgery to remove the tumor may cause temporary or permanent changes in neurological function, depending on what structures need to be manipulated during the operation. Radiation therapy, which targets tumor cells with high-energy beams, can affect normal tissue as well. Chemotherapy medications travel throughout the body and can cause various side effects as they work to kill cancer cells.^[14]

The location of the tumor and its molecular characteristics can influence how aggressively it behaves. Some malignant ependymomas may grow relatively slowly despite being classified as grade 3, while others may grow very rapidly. Understanding these individual differences helps doctors tailor treatment plans to each patient’s specific situation.^[2]