Ependymoma

Ependymoma Overview

An ependymoma is a tumor that forms in the brain or spinal cord from ependymal cells. These cells are one of the three types of glial cells that support the central nervous system (CNS).

Typically, ependymal cells help make and regulate cerebrospinal fluid (CSF), which cushions and protects the brain and spinal cord. They form a thin layer lining the brain’s ventricles and the spinal cord’s central canal—hollow, CSF-filled areas near the center of each organ. In the case of an ependymoma, ependymal cells begin to grow uncontrollably and form a tumor, which can press on nearby tissues or block the flow of CSF and trigger a host of symptoms.

Ependymomas can form in several areas of the central nervous system (CNS), including:

• The brain: Ependymomas are commonly found in and around the ventricles, especially in children, but also occur in adults.
• The spinal cord: Spinal cord ependymomas are more common in adults. They generally form in and around the central canal and can cause symptoms related to nerve compression.
• The fourth ventricle: Ependymomas often occur near the fourth ventricle, a CSF-filled space in the lower part of the brain. These tumors can block the flow of cerebrospinal fluid and lead to increased pressure within the brain.

The World Health Organization (WHO) groups ependymomas into three grades based on their characteristics and behavior. They are:

• Grade 1: This ependymoma grade is characteristic of subependymomas. They are slow-growing, less likely to spread, and typically found in the ventricles of the brain.
• Grade 2: This is the most common grade of ependymoma. Grade 2 ependymomas have a moderate growth rate. They can be found in the brain and the spinal cord and have different characteristics and genetics based on their location. A similar but different type of tumor called myxopapillary ependymoma is classified as a grade 2 tumor. It is found most frequently at the bottom of the spinal cord. They can spread to other parts of the central nervous system.
• Grade 3: These ependymomas are fast-growing, malignant, and are found in the brain and spine. They are more likely to recur after treatment and may spread to other parts of the CNS.

What causes ependymoma?

The exact cause of ependymoma is not fully understood. Most ependymomas are sporadic, meaning they happen without a clear or known cause. However, there are a few contributing factors and genetic links that researchers have identified, including:

• Genetic mutations: Ependymomas are sometimes associated with specific genetic mutations, but these changes in cell DNA typically happen during a person’s life rather than being inherited from parents. The most common mutations vary by location. YAP1 and ZFTA fusions are more common in ependymomas of the brain above the cerebellum. Two types of ependymoma are found in the posterior fossa (near the cerebellum), designated group A and B. Spinal ependymomas frequently have NF2 mutations. MYCN-amplified ependymomas are grade 3 by definition and are more aggressive and harder to treat.
• Chromosomal changes: In some cases of ependymoma, researchers have identified specific chromosomal abnormalities or alterations that may contribute to tumor formation. For example, some ependymomas have abnormalities in chromosome 22, especially those affecting the spinal cord.
• Neurofibromatosis type II (NF2): A rare genetic disorder that increases the risk of developing tumors in the central nervous system, NF2 is not a common cause of ependymomas. However, people with this condition are more likely to develop spinal ependymomas than the rest of the population.
• Developmental origin: During early development, it’s thought that something may go wrong in how ependymal cells in the brain and spinal cord divide and grow, leading to the formation of a tumor later in life.

In many cases, it’s unknown why an ependymoma develops. Most people don’t have a family history of brain tumors or spine tumors, and there is no clear link between lifestyle and environmental elements, such as exposure to toxins, chemicals, or radiation.

If an ependymoma is in your spinal cord, you might experience the following symptoms:

• Back pain: This is one of the most common symptoms of a spinal ependymoma, especially if the back pain originates from your middle or lower back.
• Numbness or tingling: You may experience numbness, tingling, or pins-and-needles sensations in your arms or legs, depending on where the tumor presses on the spinal cord.
• Weakness or difficulty walking: If a tumor affects the motor nerves in your spinal cord, it can cause weakness, problems walking, or even paralysis in severe cases.
• Loss of bladder or bowel control: If an ependymoma affects the lower spinal cord, bladder or bowel function can be altered.

These symptoms can overlap with those caused by other conditions, so it’s essential to consult a healthcare professional if you’re experiencing one or more of them. Early detection improves outcomes, especially in the case of tumors.

Ependymoma Diagnosis

Diagnosing an ependymoma can require multiple steps to determine the extent of the tumor. Your healthcare provider will use a combination of imaging studies, laboratory tests, and occasionally more invasive procedures for the most accurate diagnosis.

The most common diagnostic tests for ependymoma include:

• Physical and neurological exam: First, your provider will begin by reviewing your symptoms, medical history, and any risk factors you may have. Next, your doctor will complete a neurological examination to check your vision, coordination, reflexes, strength, and other functions controlled by the brain and spinal cord.
• Magnetic Resonance Imaging (MRI): Imaging studies are crucial in visualizing brain and spine abnormalities. The most common test for diagnosing an ependymoma, an MRI, uses strong magnets and radio waves to provide detailed brain and spinal cord images to determine a tumor’s location, size, and characteristics. Sometimes, a special dye is injected to more clearly highlight the tumor and show how it’s affecting your surrounding brain or spinal cord tissue.
• Computed Tomography (CT): CT scans rely on X-rays to create detailed cross-sectional images of the brain, helping to detect tumors while evaluating their size and location.Sometimes, a CT scan may provide additional information about bone involvement in the spinal cord region.
• Biopsy: To confirm the diagnosis of an ependymoma, your doctor may recommend a biopsy. During a biopsy, a small tumor sample is removed and sent to a pathology laboratory for analysis. There, pathologists examine the tissue under a microscope to determine the type of cells present and other important characteristics that guide treatment decisions. For tumors in the brain, a biopsy is typically done surgically or through stereotactic biopsy. For spinal ependymomas, a biopsy may be taken during surgery or through a small needle.
• Lumbar puncture: Also known as a spinal tap, a lumbar puncture involves a needle inserted into the lower back to collect cerebrospinal fluid (CSF) to test for the presence of cancerous cells. This test can detect whether your tumor has spread within the central nervous system (CNS).
• Positron Emission Tomography (PET) scan: PET scans evaluate the metabolic activity of brain tumors to determine their aggressiveness.

Each test will help your healthcare providers confirm the extent of your ependymoma. If needed, additional tests may be run to assess its effects.

Surgical Treatments

Surgery is typically the first and most crucial step in treating ependymomas. The goal is to remove as much of the tumor as possible without damaging any critical areas of the brain or spinal cord. When an ependymoma can be entirely removed, this is known as a complete resection.

In some cases, complete removal won’t be possible because of your tumor’s location. That said, a partial resection can still be beneficial and complemented by additional therapies like radiation.

• Craniotomy: A craniotomy is the most common surgery for a brain tumor, including ependymomas. During a craniotomy, a neurosurgeon will make an incision in the scalp, remove a portion of the skull, and access the brain to remove the tumor, all while using intraoperative imaging and highly specialized tools to visualize and safely remove the abnormal tissue.
• Laminectomy or laminoplasty: A laminectomy or laminoplasty is performed for ependymomas in the spinal cord. Spinal ependymomas are often easier to remove because they’re more accessible and less intertwined with critical structures. In a laminectomy, the neurosurgeon removes part of the vertebral bone, known as the lamina, to access the spinal cord and remove the tumor. In a laminoplasty, the lamina is not entirely removed but repositioned to allow access to the spinal cord and then replaced after tumor removal.
• Endoscopic surgery: Endoscopic surgery may be used for some ependymomas—particularly those located in ventricles. A small incision is made in the skull, and a neuroendoscope, or a small, flexible tube with a camera and surgical tools, is inserted into the brain to remove the tumor with minimal disruption to surrounding brain tissue. Endoscopic surgery is minimally invasive, meaning smaller incisions and shorter recovery times.
• Ventriculoperitoneal shunt: If the ependymoma blocks the flow of cerebrospinal fluid (CSF) and causes fluid buildup in the brain, a ventriculoperitoneal (VP) shunt may be inserted to drain the excess fluid and relieve pressure. This procedure does not directly treat the tumor but helps manage its complications.

While ependymomas in the brainstem or spinal cord can be challenging to remove, the use of microsurgery and intraoperative imaging continues to improve outcomes.

Chemotherapy

Chemotherapy is used for ependymomas when surgery and radiation do not control the cancer cells. Various chemotherapy regimens can be used, with the combination of the chemotherapies lapatinib and temozolomide having the most evidence of efficacy.  

Corticosteroids

This class of medication can be used in the short term to reduce inflammation and swelling of the brain and spine caused by an ependymoma. While not a long-term treatment, corticosteroids can help relieve inflammation and ease symptoms like headaches or other neurological issues.

Targeted Therapy

Researchers continue exploring new treatments that target specific molecular features of tumor cells. For ependymomas, targeted therapies may focus on specific genetic mutations, such as mutations in the NF2 gene, found in some cases.

One Central Location with Multiple Treatment Options

At Barrow Neurological Institute’s world-class Brain and Spine Tumor Program, we treat people with complex tumors like ependymomas in one robust, full-service location. Our sophisticated multidisciplinary team—neurosurgeons, head and neck surgeons, neuro-oncologists, medical oncologists, and radiation oncologists, to name a few—can offer you the latest treatments for head and neck cancers, including metastatic cancers.

We also give our patients access to various neuro-rehabilitation specialists to maximize independence. Neuro-rehabilitation can include physical therapy to help you regain strength and balance, speech therapy to support speaking, expressing thoughts, or swallowing, and occupational therapy to aid you in managing daily activities like bathing, dressing, and using the bathroom. Treating a brain or spinal cord tumor is about more than extending your life—it’s also focused on enhancing your quality of life.

Clinical Trials

In partnership with the Ivy Brain Tumor Center, Barrow Neurological Institute is proud to be one of the country’s largest sites for neurological clinical trials. 

Clinical trials are part of the cancer research process to determine if new treatments are safe, effective, or even better than the current standard treatment. Although not yet FDA-approved, clinical trials can be the best option for those with difficult-to-treat tumors to improve the odds of finding an effective treatment for them and for future patients.