Subependymal giant cell astrocytoma
What is a subependymal giant cell astrocytoma (SEGA)?
The subependymal giant cell astrocytoma (SEGA) is a benign brain tumor that is rare. It is produced under the ependyma and, according to the WHO health classification, is classified as tumor grade I. Giant cell astrocytomas are understood to mean larger tumors in which calcification occurs. Apart from astrocytes, which are star-shaped small cells, the giant cell astrocytomas also have extensive nerve cells.
These show up exclusively in this type of tumor. This makes them easy to distinguish from rapidly growing isolated astrocytomas. The latter are considered to be malignant brain tumors and are not associated with tuberous sclerosis (TSC), as is the case with subependymal giant cell astrocytoma. In addition, the growth of giant cell astrocytomas is much slower.
The exact causes of a subependymal giant cell astrocytoma are unknown. They occur primarily in children and young adults. The age of the disease is under 20 years. Not infrequently, there is a connection between the expression of a giant cell astrocytoma and tuberous sclerosis. Thus, in about 15 percent of all patients who are suffering from tuberous sclerosis, a subependymal giant cell astrocytoma.
Occasionally, the tumor is also the first sign of tuberous sclerosis. Tuberous sclerosis is an inherited disease that is transmitted as an autosomal dominant disorder and is associated with various symptoms. The occurrence of a subependymal giant cell astrocytoma is considered to be an important criterion in the diagnosis of tuberous sclerosis.
The subependymal giant cell astrocytoma usually settles almost exclusively in the region of the Foramen Monroi. At the tumors extensive calcification herds are to be found. Not infrequently, they are penetrated by partitions and are cystically transformed. Other typical features of subependymal giant cell astrocytoma include relatively few mitoses as well as extensive multinucleated cells.
Symptoms, complaints & signs
The development of a subependymal giant cell astrocytoma is almost always due to the lining of the brain wall, which is located inside the brain. As the growth of the tumor progresses and grows larger, it can cause significant discomfort. This includes obstructing the outflow of cerebrospinal fluid (cerebrospinal fluid) from the cerebral chambers. This in turn creates pressure on the brain tissue.
Normally, the brain water that forms in the ventricles can flow freely into the outer CSF spaces. In this way, the brain is flushed with brain water from both the outer and the inner side, whereby a padding to the cranial walls is achieved. Due to a drainage obstruction due to a subependymal giant cell astrocytoma, however, it comes to accumulation of cerebral water within the brain chamber, what medical professionals call hydrocephalus (water head).
As pressure on the tissues of the brain increases due to obstruction, those affected suffer from nausea, vomiting, headache, decreased visual acuity, and visual field loss. Likewise, epileptic seizures and disturbances of consciousness are possible. In the worst case, the patient may even fall into a coma.
On the other hand, if there is a smaller subependymal giant cell astrocytoma, this usually does not lead to discomfort. Often the small tumors are detected during routine examinations by imaging techniques.
Diagnosis & disease course
If there is a suspicion of a subependymal giant cell astrocytoma, magnetic resonance imaging (MRI) is usually performed. Thus, the small tumors can be well represented by means of magnetic resonance imaging. To detect calcifications, computed tomography (CT) is useful. Thus, the calcification foci are displayed within a tumor mass, which is located on the wall of the 3rd ventricle.
Important indications are the location of the astrocytoma, the age of the patient as well as the radiological specificities of the tumor. Histologically, the diagnosis of SEGA can be made by tissue sampling (biopsy) or histopathological examination.
The course of a subependymal giant cell astrocytoma depends on whether a basic disease is present. Especially tuberous sclerosis plays a role here. Without the treatment of occlusive hydrocephalus, there is a risk of permanent damage to the nerve tissue due to sustained pressure. Not infrequently, the giant cell astrocytoma is surgically removed.
A subependymal giant cell astrocytoma can cause a number of complications. Increasing pressure on the brain tissue causes symptoms such as nausea, vomiting and headache, which increase in intensity and duration as the disease progresses. In addition, visual disturbances such as visual field defects, diminished visual acuity and double images occur, which considerably limit the affected person in his everyday life and can lead to accidents.
Also epileptic seizures and disturbances of consciousness are conceivable and in turn connected with serious complications. In the worst case, the patient loses consciousness. If the giant cell astrocytoma is not treated, there is a risk of damage to the nerve tissue and, as a result, permanent neurological disorders. The surgical removal of the brain tumor involves the usual risks: bleeding, nerve cord injury and brain tissue, and infection.
Wound healing disorders may occur after surgery. The concomitant painkillers and tranquilizers can cause gastrointestinal discomfort, pain and other complications. If the patient is on medication, the mTOR inhibitors may occasionally cause non-infectious pneumonitis, stomatitis, or rash. In addition, allergic reactions and symptoms of intolerance may occur and delay recovery.
When should you go to the doctor?
In this disease should always be consulted a doctor. In general, an early visit to the doctor has a positive effect on the further course of the disease and can also prevent further complications. For this reason, should be contacted at the first signs and symptoms, a physician, so it does not lead to a worsening of the symptoms.
The doctor should be consulted if the person suffering from very severe headache. In most cases, these pains occur permanently and without any particular reason. Furthermore, persistent nausea, which may be associated with vomiting, also indicates this disease and should also be investigated. In an advanced stage, the disease can also lead to an epileptic seizure.
First and foremost, a GP can be consulted. A specialist then performs various examinations to detect the tumor. The further course and also the life expectancy strongly depend on the expression of the tumor. If an epileptic seizure occurs, an emergency doctor must be called immediately or a hospital must be visited.
Therapy & Treatment
The treatment of a subependymal giant cell astrocytoma depends on its extent. If the tumor is of small size and does not cause any discomfort, regular check-ups by magnetic resonance imaging are sufficient. Thus, in the context of magnetic resonance tomography or computed tomography congestion of the liquor can be determined by the widening of the brain chambers. The check-ups take place at shorter intervals.
However, if a subependymal giant cell astrocytoma causes discomfort or if the cerebral chambers widen, surgical intervention is usually performed. As part of the operation, the skull is opened from the top. With the help of two brain spatulas, the surgeon pulls the brain tissue slightly apart. Between the spatulas, a gap is formed through which the surgeon performs the procedure and surgically removes the tumor.
After removal of the subependymal giant cell astrocytoma, the symptoms usually return quickly. If an operative procedure is not considered suitable, a drug therapy can also take place. To this end, the patient receives mTOR inhibitors in the form of tablets that inhibit the regulator protein mTOR and restore the balance between activating and inhibiting influences.
Preventive measures against the development of a subependymal giant cell astrocytoma are not known. Thus, the benign tumor is often caused by tuberous sclerosis, which is one of hereditary diseases.
The treatment of a subependymal giant cell astrocytoma should be followed by extensive follow-up. This consists mainly of regular neurological examinations. Important is the timely detection of long-term damage, as well as their treatment. In addition to the EEG and the neurological examination of motor skills and reflexes, imaging techniques (MRI, CT) are also used.
If long-term neurological damage such as epilepsy or chronic headache develops, these must be treated separately. In addition, a study on tuberous sclerosis should be carried out, as it is often expressed initially in subependymal giant cell asrocytomas. If tuberous sclerosis is present, its symptoms must be further treated. If CSF pressure is permanently increased as a result of the subependymal giant cell astrocytoma, it must be checked regularly.
In addition to the use of drugs that reduce the CSF pressure (Glaupax), regular lumbar punctures with a CSF take place. In addition, it may be necessary to use a shunt that permanently releases CSF from the head. If the subependymal giant cell astrocytoma has been surgically removed, it may be necessary to treat the consequences of surgery (visual field defects, paralysis).
For this, a comprehensive rehabilitation therapy may be necessary. In addition, patients suffering from a subependymal giant cell astrocytoma should seek a cancer-promoting lifestyle. In addition to abstaining from smoking, artificial sweeteners and contact with chemicals and carcinogenic substances should also be avoided.
You can do that yourself
A subependymal giant cell astrocytoma is treated depending on its size and location. Smaller tumors in many cases are without significant discomfort and the self-help measures are limited to the strict observance of the regular check-ups.
If symptoms occur, surgery is required. After such a procedure, initially a longer hospital stay is indicated. Those affected should adhere to the medical guidelines and rest. The complaints usually resolve quickly. Even after the operation medical check-ups are needed. Affected persons speak best with the responsible physician about any aftercare measures.
Even patients can support recovery through sports and a healthy lifestyle. The diet should be adjusted to avoid inflammation of the surgical wound and other discomforts. In addition, it is important to pay attention to physical signals to quickly recognize recurrences or other complications. The doctor should be informed about unusual symptoms. Accompanying this, a look into the family history is recommended. If there are already cases of tuberous sclerosis in the immediate family, the likelihood of causing further astrocytomas is high.