What is Ependymoma?
Ependymomas are types of brain tumors that usually form in the cells lining the pathways that fluid flows through in the brain and spinal cord. Rarely, they can occur outside the central nervous system (CNS), which is the brain and spinal cord, or even within the brain tissue itself. These tumors consist of genetically different groups and generally affect children more than adults.
What Causes Ependymoma?
Ependymomas are a type of brain tumor that, despite resembling each other under a microscope, can behave differently based on where they occur in the nervous system. The traditional method of categorizing these tumors based solely on what they look like under the microscope hasn’t consistently predicted a patient’s prognosis in past studies. This means that even ependymomas that look similar can result in significantly different health outcomes.
Recent research suggests that ependymomas can be better classified by the type of original cells from which they grow. This might explain why tumors that look the same under a microscope can result in diverse health scenarios.
Further research has found several genetic abnormalities associated with ependymomas. The abnormalities impacted significant areas of the patient’s genetic makeup. It was found that ependymomas can be linked with specific cancer-promoting substances and molecular subgroups. These correlations may provide a more accurate prediction of a patient’s health outcome compared to simply categorizing tumors based on what they look like under a microscope.
Risk Factors and Frequency for Ependymoma
Ependymomas, which are a type of brain tumor, affect people of all ages but are more common in children. In fact, they are the third most common type of brain tumor found in kids. According to the Central Brain Tumor Registry of the United States, ependymal tumors, which include ependymomas, make up 1.7% of all brain and central nervous system tumors. The average age of a person diagnosed with this type of tumor is 44.
In children, brain tumors are the leading cause of death from solid tumors. The most common types of brain tumors in children include:
- Medulloblastomas
- Pilocytic Astrocytomas
- Brainstem Gliomas
- Ependymomas
Signs and Symptoms of Ependymoma
Ependymomas are tumors that form in different parts of the central nervous system (CNS). Because of this, their symptoms can vary significantly. Some people with an ependymoma may experience sudden symptoms like high pressure within the skull, which can cause nausea and vomiting. Others might have a slower onset of symptoms that progress over a longer period.
The term “ependymoma” actually refers to the type of cell the tumor is made from, and not its location. These types of tumors are most commonly found in three areas: above the tentorium (the membrane that separates the cerebrum from the cerebellum), within the spinal cord, or below the tentorium.
If an adult patient has had prolonged symptoms and brain imaging reveals a non-enhancing and well-bounded lesion within a ventricle of the brain (a cavity filled with cerebrospinal fluid), doctors might suspect an ependymoma. In a CT scan, this lesion looks the same as normal brain tissue. Similarly, in T1 images from an MRI scan, the lesion also has the same intensity as normal tissue.
Testing for Ependymoma
Ependymomas, a type of brain tumor, have traditionally been classified using a system developed by the World Health Organization (WHO). This system was primarily designed to help predict how the tumor might behave based on its physical characteristics. However, in the case of ependymomas, the genetic makeup of the tumor may provide more accurate information than just its physical properties.
The WHO classification system was based on different physical characteristics of the tumor. But this system doesn’t always give a reliable prediction of how the tumor will behave in people with ependymoma. Thanks to advances in our understanding of how these tumors develop, the WHO updated their classification system in 2016 to include the presence or absence of specific genetic changes known as RELA fusion in ependymomas.
Research has identified nine different subgroups of ependymomas, which are associated with different locations in the body, genetic changes, and patient characteristics. These new findings mean that we have the potential to improve how we diagnose, manage, and predict the outcome for ependymomas based on their specific subgroup.
Currently, there are no molecular or immunohistochemical markers (proteins that can be identified in a laboratory test) routinely used to diagnose ependymomas. This means doctors have to rely on other types of tests and procedures.
Treatment Options for Ependymoma
Ependymal tumors are a rare type of brain tumor, making up about 1.7% of all brain tumors. Because they are so rare, it’s hard to say for certain what the best treatment plan is. However, looking back at past studies, we’ve found that patients who had surgery to remove the tumor and then radiation therapy afterwards tended to live longer. At the moment, there’s not enough evidence to say for sure whether chemotherapy is helpful for adult patients with ependymal tumors.
Right now, there aren’t any set rules on how treatment options should change based on the specific characteristics of the ependymal tumor a patient has. Still, it’s generally agreed upon that patients with a certain type of ependymal tumor (called PF-EPN-A positive ependymoma) who are older than 12 months should have surgery to remove as much of the tumor as possible, while prioritizing safety. After surgery, these patients should also have local radiotherapy, which is a type of cancer treatment that uses high-energy rays or particles to destroy cancer cells.
For ependymal tumors inside the skull (intracranial ependymomas), surgery is usually the main treatment. Studies have shown that patients tend to do better and survive longer if the entire tumor can be removed without leaving any behind, compared to partially removing the tumor. As mentioned before, there’s currently not enough evidence to confidently suggest chemotherapy as a treatment option.
What else can Ependymoma be?
When a doctor is looking at tumors in the back part of the brain, known as the posterior fossa, they consider the following possibilities:
- Astrocytoma
- Medulloblastoma
- Choroid plexus tumors
They also have to consider different possibilities for tumors that are above the tentorium in the brain, also called supratentorial tumors. They could be:
- Glial tumors
- Choroid plexus carcinoma or papilloma
- Embryonal tumors
What to expect with Ependymoma
Intracranial ependymomas, a type of brain tumor, can have different outcomes based on several factors. One key factor strongly linked to recovery is the extent to which the tumor is removed during surgery. These types of brain tumors are typically locally invasive, meaning they mainly affect one area, and don’t often spread to other parts of the body.
According to the World Health Organization’s (WHO) grading system, ependymomas are classified into different grades. Grade III ependymomas are generally associated with a worse prognosis than grade II.
Patients who have the entire tumor surgically removed, leaving no traces of the disease, often have better outcomes and live longer compared to those who have only part of the tumor removed. This is why doctors usually recommend an aggressive surgical approach to completely remove the tumor.
However, outcomes can also differ based on the tumor’s location. Ependymomas located in the lower part of the brain, called infratentorial ependymomas, generally have a very good prognosis, even without treatment. Those located in the upper part of the brain, known as supratentorial ependymomas, often have a higher WHO grade, meaning they’re more serious, and unfortunately, patients don’t usually live as long even with treatment and surgery.
A lot depends on the patient’s individual circumstances, including the location of their tumor, what type of treatment they receive and the WHO grade of their tumor. Past studies have shown that surgery that removes the entire tumor provides the best possible outcome. Patients with WHO grade II tumors have a better outcome after aggressive tumor removal, especially when coupled with a treatment called external beam radiation therapy, whereas those with WHO grade III tumors fare better when part of the tumor is removed alongside radiation therapy.
Last but not least, patients with tumors located in the lower part of the brain generally have a better chance at a disease-free life following partial tumor removal and radiation therapy.
Possible Complications When Diagnosed with Ependymoma
People who have survived central nervous system (CNS) tumors for a long period may face a variety of problems. These problems can include issues with the nervous system, mental capabilities, hearing loss due to damage to the sensory nerves, hormonal and growth irregularities, and the development of other types of cancers. Adults specifically may encounter long-term issues such as constant tiredness, numbness and tingling sensations, pain, and troubled sleep patterns.
Common Long-Term Complications:
- Nervous system problems
- Mental capabilities limitations
- Sensorineural hearing loss
- Hormonal and growth issues
- Developing other cancers
- Constant tiredness
- Numbness and tingling
- Pain
- Troubled sleep patterns
Preventing Ependymoma
Patients should be given advice about their future health, especially if they have end-stage brain tumors. End-of-life care that focuses on providing relief from disease and treatment symptoms – known as palliative care – can be greatly beneficial. Both the patient and their family often find that receiving guidance and counseling early on helps them prepare for what to expect. Additionally, comfort measures, such as managing pain and emotional support, can enhance their well-being. It’s important that palliative care involves a team of health professionals to address the various needs that patients may encounter during this time.
