What is an Ependymoma?
An ependymoma is a tumor that arises from the ependymal cells, which line the ventricles of the brain and the central canal of the spinal cord. Ependymomas are typically found in three major locations: the posterior fossa, the supratentorium, and the spinal cord. Over 90% of ependymoma arise from the brain and 10% arise for the spinal cord. Ependymomas rarely spread (metastasize) from their site of origin.
Ependymomas are categorized by their microscopic appearance and are graded according to the World Health Organization (WHO) classification system. There are two different types of WHO Grade I Ependymoma: Subependymoma, which is very rare in childhood and grows within the ventricles of the brain, and Myxopapillary Ependymoma, which is rare but more commonly seen in teens and typically arises from the region of the cauda equina located at the base of the spinal cord. Grade II Ependymomas are often called “Differentiated Ependymoma” and are located within the ventricles of the brain or within the central canal of the spinal cord. Grade III Ependymomas are termed Anaplastic Ependymoma and are usually located with the ventricles of the brain. Subependymoma are benign tumors. Myxopapillary Ependymoma and WHO grade II and III ependymoma are malignant (cancer).
Ependymomas are the third most common type of central nervous system (CNS) tumor in children (following astrocytoma and medulloblastoma). Approximately 200 cases of childhood ependymoma are diagnosed in the U.S. each year. Ependymomas account for 6-12% of brain tumors in children less than 18 years of age, but 30% of brain tumors in children less than three years of age. The average age at diagnosis is four to six years.
What are the symptoms of an Ependymoma?
The symptoms of ependymoma are determined by where they are located within the brain or spine. Ependymoma of the brain often cause hydrocephalus due to their location within the ventricle, resulting in symptoms of increase intracranial pressure (headache, vomiting, poor balance, and decreased level of consciousness). Supratentorial ependymoma can present with headache, weakness, visual field cut or seizures. Posterior fossa ependymoma can present with headache, double vision, other cranial nerve dysfunction, and torticollis (turning the head to one side). Spinal cord ependymoma may present with weakness and/or loss of sensation, pain, and bowel or bladder dysfunction. Myxopapillary ependymoma frequently presents with severe pain in the lower back and legs.
How is an Ependymoma diagnosed?
Patients who have a brain or spinal cord tumor will undergo an MRI of the brain and spine to further define the location of the tumor and to assess if there is any metastasis (spread) of the tumor. A biopsy of the tumor is required to make the final diagnosis of an ependymoma and to subtype the ependymoma according to WHO guidelines. Patients with ependymoma of the brain require a spinal tap (lumbar puncture) to assess for any spread of the tumor through the spinal fluid.
How is an Ependymoma treated?
The initial treatment for ependymoma is surgery. In general, the neurosurgeon will attempt to remove as much of the tumor as possible, without causing damage to the normal brain. A complete resection, confirmed by post-operative MRI or CT scan, correlates highly with a favorable prognosis. Although total resection is optimal, it is not always possible because vital structures can be involved by the tumor.
Spinal Cord Ependymoma: Complete surgical resection is typically possible for ependymoma/myxopapillary ependymoma of the spinal cord. Following complete removal, no further treatment is needed.
Supratentorial Ependymoma: Ependymoma located in the supratentorial location will often undergo a complete surgical removal. If the pathology of the tumor is WHO grade II no further treatment is indicated. If the pathology of the tumor is WHO grade III, radiation therapy should be given to the tumor bed to give the best chances that the tumor will not recur. In cases where the tumor has been incompletely removed, either a second surgery should be performed immediately to remove the residual tumor or a short course of chemotherapy should be given to shrink the remaining tumor followed by a second surgery to remove any residual tumor. If the tumor is only partially removed or if the tumor is WHO grade III than radiation therapy to the tumor bed is recommended.
Posterior Fossa Ependymoma: Ependymoma located within the posterior fossa are believed to always have residual microscopic tumor cells present, even after a complete removal. It is recommended that all patients receive radiation therapy to the tumor bed. In cases where the tumor has been incompletely removed, either a second surgery should be performed immediately to remove the residual tumor or a short course of chemotherapy should be given to shrink the remaining tumor followed by a second surgery to remove any residual tumor. It is believed that all posterior fossa ependymoma should receive radiation therapy to the tumor bed.
Children who have tumor spread within the cerebrospinal fluid (metastatic disease) benefit from craniospinal radiation therapy.
The role of chemotherapy after radiation therapy is unclear. Although chemotherapy has been extensively researched in children with ependymomas, there is little clinical evidence that chemotherapy improves survival of children with this type of tumor. Chemotherapy is reserved
for patients with residual tumor following surgery (incomplete surgical resection) with the goal to shrink the tumor and make it more amenable to a second surgery. Chemotherapy is also used in children younger than three years of age in an attempt to delay radiation therapy until they are older.
The extent of surgical resection is the primary factor influencing survival with a significantly better prognosis for patients with completely resected tumors.
About treatment for ependymoma at Children’s Minnesota
Our cancer and blood disorders program consistently achieves excellent results ranking it in the top ten programs in the United States. Children’s Minnesota treats the majority of children with cancer and blood disorders in Minnesota and provides patients access to a variety of clinical trials using ground-breaking new treatments. Through our renowned program, patients experience unparalleled family support, a nationally recognized pain management team, and compassionate, coordinated care.
If you are a family member looking for a Children’s neuro-oncologist, please call our clinic at 612-813-5940.
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Additional information on Ependymoma
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