What is an ependymoma?
An ependymoma is a rather rare tumour that develops either in the brain (glioma) or in the spinal cord. It originates from the ependymal cells, i.e. the ventricular system of the inner brain chambers and the central canal of the spinal cord. Between 5 and 10 per cent of all gliomas are due to an epensymoma and are the third most common tumour disease of the central nervous system in childhood, along with astrocytomas and medulloblastomas. Children around the age of six in particular tend to develop an ependymoma. In adults, however, ependymoma is relatively rare and only accounts for between 2 and 3 percent of all brain tumours.
While ependymomas in children tend to develop in the back of the skull and in the spinal cord, ependymomas in adults develop mainly in the cerebrum.
How does an ependymoma develop?
Ependymomas in children and adults do not differ much in the shape of the tumour. Ependymomas grow from the cells that make contact between the cerebrospinal fluid and normal brain tissue. This also explains the place of origin of an ependymoma: as a rule, they are found in the cerebrospinal fluid chamber of the brain stem, the lateral chambers of the cerebral hemispheres, in the posterior fossa or in the spinal canal.
However, doctors still disagree about the exact causes of ependymomas. However, they assume that people who have already undergone radiation therapy as part of a previous cancer illness have an increased risk of developing an ependymoma. This is especially true for children who have had leukaemia or the malignant eye tumour retinoblastoma. If an ependymoma develops in the spinal cord, this can often be due to the hereditary disease neurofibromatosis type 2.
What are the different types of ependymomas?
The World Health Organisation (WHO) classifies ependymomas into the following subtypes:
- Myxopappillary ependymoma (WHO grade I): benign brain tumour that usually forms in the lowest spinal cord area and occurs primarily in adults
- Subependymoma (WHO grade I): benign brain tumour which is usually diagnosed by chance and grows as a bulbous protrusion into the interior of the cerebral ventricle
- Ependymoma (WHO grade II): Brain tumour that grows slowly and is confined to the inner cerebral ventricle or spinal cord
- Anaplastic ependymoma (WHO grade III): Brain tumour which occurs and grows rapidly, especially in children
Whereas first- and second-degree ependymomas usually grow slowly and are limited in size, third-degree ependymomas grow rapidly and also extend beyond the neighbouring brain tissue.
What are the symptoms of an ependymoma?
The symptoms of an ependymoma always depend on the type of tumour. An alplastic ependymoma can lead to a build-up of cerebrospinal fluid and thus increase the intracranial pressure. This is associated with headaches and nausea, which cannot be relieved by medication. The headaches usually occur at night or in the early hours of the morning and do not go away during the day. It is also typical that the headaches recur regularly and intensify over days and weeks. As the intracranial pressure increases, the nausea may also increase, causing the patient to vomit more often. Many also complain of fatigue, tiredness or go into a comatose state.
Especially in younger children, an ependymoma can increase the circumference of the head (macrocephalus). Some also notice the tumour through the occurrence of seizures or problems with seeing, walking, concentrating and sleeping. In rare cases, an ependymoma can cause paralysis.
How is an ependymoma diagnosed?
An ependymoma is diagnosed using standard imaging techniques. A magnetic resonance imaging (MRI) scan can localise the tumour and determine its size and extent. Since an ependymoma can spread through its connection to the cerebrospinal fluid (CSF) pathways, albeit rather in exceptional cases, an examination of the cerebrospinal fluid (CSF diagnostics) and the central nervous system is often also ordered. Here, individual tumour cells can be detected. The doctor will also take a tissue sample of the tumour in order to carry out a fine tissue examination of the tumour. In this way, the doctor can determine the degree of tumour and adapt the therapy to the patient in the best possible way.
How is an ependymoma treated?
Because ependymoma is a relatively rare type of tumour, it is difficult to give clear treatment recommendations. The type of treatment depends on the age of the patient, the patient's general health, the size of the tumour and the location of the tumour.
As a rule, an attempt is made to surgically remove the ependymoma in order to alleviate possible symptoms. Surgery is usually easier in the spinal cord than in the brain. If it is not possible to remove the tumour completely, the operation is followed by local radiotherapy. This is also carried out if the tumour is aggressive in terms of fine tissue and could be completely removed surgically in order to prevent possible regrowth. Whether chemotherapy is ordered in addition to radiotherapy is probably always at the discretion of the treating doctor. So far, chemotherapy has only had a limited effect on childhood ependymomas. If, on the other hand, it is a rather rare ependymoma that has already formed metastases, radiation treatment of the entire central nervous system must also be carried out.
In addition to these treatment methods, other medications can also be used to relieve symptoms such as headaches or nausea. Therapy with cortisone preparations is also an option. They cause the brain tissue to swell and in this way also reduce the intracranial pressure.
What is the prognosis for an ependymoma?
The prognosis for an ependymoma is closely linked to the success of the operation. If the tumour is in the spinal canal and can be completely removed, the chances of a complete recovery are good. In the case of a tumour of the head and after complete tumour removal with subsequent radiotherapy, patients remain relapse-free in almost 80 percent of all cases.