An oligoastrocytoma is a mixed glioma that has both parts of an oligodendroglioma and parts of an astrocytoma. The brain tumors produce general signs of intracranial pressure.
What is an oligoastrocytoma?
The oligoastrocytoma is a hybrid of an astrocytoma and an oligodendroglioma. The oligodendroglioma, formerly also called oligodendrocytoma, is a tumor that starts from the oligodendrocytes. It is one of the neuroepithelial tumors. The oligodendrocytes are cells of the glia. Glia is a collective term for all cells in nerve tissue that are not nerve cells. See ablogtophone for HC which stands for Hypertensive Crisis.
The glial cells often assume support and holding functions in the nervous system. Astrocytomas are the most common tumors in the brain. They occur predominantly in middle age and arise from the astrocytes. Astrocytes, like oligodendrocytes, belong to the glial cells and thus to the supporting tissue.
Oligodendrogliomas, astrocytomas and thus also oligoastrocytomas belong to the gliomas. Gliomas are tumors of the central nervous system. In most cases they occur in the brain, but they can also arise in the spinal cord and cranial nerves.
The cause of oligoastrocytomas is still unknown. Individual cases show that the tumors appear after CNS radiation or brain injuries. In these cases, they appear to develop from the scar tissue. Oligoastrocytomas have also been observed in multiple sclerosis . It is also discussed whether there is a genetic predisposition for oligoastrocytomas. The evidence for this hypothesis is contradictory.
Symptoms, Ailments & Signs
The most common symptom of oligoastrocytoma is the epileptic seizure. It occurs in more than 50 percent of patients and is due to infiltration and damage to neighboring nerve cells. As the tumor grows steadily in the skull, intracranial pressure increases. Other symptoms of oligoastrocytoma are therefore signs of increased intracranial pressure.
Signs of intracranial pressure include nausea and vomiting. The patients suffer from sometimes very severe headaches and fatigue. You are restless and have a slow heartbeat. The blood pressure, on the other hand, is elevated. With the help of this so-called pressure pulse, the body tries to continue to ensure blood circulation despite the increased intracranial pressure.
Diagnosis & course of disease
A choked disc can be diagnosed with the help of an ophthalmoscope. A choked disc is an accumulation of fluid at the junction of the optic nerve and the retina. In the ophthalmoscope, this edema becomes visible as swelling of the optic nerve head. The choked disc is usually bilateral.
If the symptoms are not recognized early and the intracranial pressure continues to rise, disturbances of consciousness occur. In the worst case, the patients fall into a coma. Personality changes can also be a sign of oligoastrocytoma. Years before the diagnosis is made, neurological signs such as headaches, paralysis or disorders of the cranial nerve function can also be seen.
For example, those affected have slight visual disturbances, dizzy spells or problems with facial expressions. The five-year survival rate for men with an oligoastrocytoma is 40 to 50 percent. After ten years, 20 to 30 percent of the patients are still alive. The prognosis is slightly better for women. The five-year survival rate here is 65 percent. After ten years, 40 percent of the patients are still alive.
If an oligoastrocytoma is suspected, imaging methods are used. The primary procedure is magnetic resonance imaging (MRI) with and without contrast agent administration. The examination findings often resemble those of a cerebral infarction. Computed tomography shows fuzzy hypodensities or edema. Cystic formations can also appear.
When examined with contrast medium, round mass effects with accumulation of contrast medium appear. Patients in whom the contrast agent accumulates in the tumor during the examination have a significantly increased risk of recurrence. Neither the CSF findings nor the cerebral angiography are abnormal. In the positron emission scan of glucose metabolism, the oligoastrocytoma appears as a cold nodule. The tissue therefore has a reduced energy and substance turnover.
Within the cold nodes, sometimes hot nodes with increased energy expenditure appear. Histologically, it is very difficult to draw a boundary between the astrocytic and the oligodendrial components. Grading according to the WHO definition is also difficult in the case of oligoastrocytomas. For example, mitosis in an astrocytoma is usually the reason for classifying the tumor as grade III.
Multiple mitoses can occur in oligodendrogliomas and the tumor is still only classified as grade II. Since the oligoastrocytoma is a mixed form of both tumors, the classifications differ depending on the neuropathologist. Since the classifications require different therapeutic concepts, the diagnostic distinction is actually very important.
The tumor in the brain generally causes the usual symptoms of a tumor. As a rule, this can also spread to other regions of the body and damage the healthy tissue there as well. In most cases, the life expectancy of the patient is significantly reduced by the mixed glioma.
Furthermore, the patients suffer from epileptic seizures and severe headaches. This pain significantly reduces the quality of life and leads to vomiting and nausea. There is also reduced resilience and fatigue in the patient. Those affected appear restless and suffer from slow breathing. It can also lead to a loss of consciousness.
The symptoms can also lead to cardiac death. It is not uncommon for personality changes or a coma to occur. Those affected continue to suffer from dizziness and blurred vision. The symptoms of mixed glioma can also cause mental disorders and depression in family members.
The tumor is treated with radiation therapy or chemotherapy. There are no complications, although chemotherapy is usually associated with various side effects. Whether there will be a reduction in life expectancy cannot generally be predicted.
When should you go to the doctor?
As a brain tumor, a mixed glioma basically belongs in the hands of a doctor, so that if a tumor is suspected, it is necessary to go to the doctor. As part of diagnostics and therapy, there will always be appointments with the doctor. Visits to the doctor are also important after the treatment in order to be able to detect and treat a possible recurrence at an early stage through checks. Directly after the treatment of a mixed glioma, these controls are usually carried out more frequently than after many years in the case of freedom from symptoms and without recurrence.
But even without an appointment with the doctor, the patient should go there for certain reasons. This is always the case when the patient feels symptoms that could indicate a relapse. The symptoms that require a doctor’s visit are varied in the case of a brain tumor and also depend on where the tumor and a possible recurrence are located.
The spectrum ranges from sensory disturbances and paralysis in the limbs to speech and vision disorders and memory problems to epileptic seizures. Radiation and chemotherapy may also require a visit to the doctor. This applies, for example, to weaknesses that can indicate a poor blood count and should be treated quickly by the doctor. The psychological stress caused by the severity of the disease is always a reason to see a doctor.
Treatment & Therapy
Surgical removal is the main focus of treatment. In the past, tumors were operated on as early as possible. Since today, thanks to improved diagnostic procedures, the diagnosis is often made before symptoms are present, it is now advocated to only operate when neurological deficits are present. Studies have shown that patients treated with radiation therapy before surgery have an increased survival rate.
However, radiation necrosis of the brain tissue can also occur during whole-head irradiation. Chemotherapy is of no importance in the treatment of oligoastrocytomas. The main cause of failure in therapy is the development of a local recurrence. If the tumor grows back after removal, a biopsy is done first. This is followed by close radiological controls. If it continues to grow, another resection will be necessary.
Outlook & Forecast
The prognosis for mixed glioma depends on several factors. The location in the brain is just as important as the size of the tumor. If it can be removed entirely, the prognosis is better than for a tumor that remains after surgery or that cannot be operated on in the first place. The shape of the tumor also plays a role. If it is more clearly defined, it can often be removed more successfully than the tumor, which grows into the tissue in terms of radiation.
The accessibility of a tumor for chemotherapy and radiotherapy also influences the prospects. A mixed glioma often has portions that respond to a particular therapy, while other portions do not. It is therefore necessary to find the right therapy that treats the tumor as a whole in the best possible way. It is also important to know that in mixed glioma some parts of the tumor can grow faster than others.
The slower the tumor spreads overall, the later the pressure increases through the skullcap as a natural border, which leads to the typical symptoms such as pain and loss of symptoms in the affected patient and can have an unfavorable effect on the prognosis. Radiation therapy is limited in Gray number. Those affected who have not yet been irradiated on their heads also have a better prognosis.
The exact origin of the oligoastrocytoma is unclear, so that there is currently no prevention. If headaches occur over a longer period of time or if neurological deficits are observed, a doctor should be consulted for clarification. The earlier the oligoastrocytoma is treated, the better the chances of recovery.
As with all tumorous diseases, close follow-up care is required after treatment has been completed. This is necessary in order to detect any new tumors or metastases at a very early stage. In the case of a brain tumor, follow-up checks are therefore scheduled several times a year at intervals of a few months.
If there are no negative abnormalities, the intervals between the next inspection will increase. An MRI or CT scan is used to check whether new growths have occurred. Precisely because malignant brain tumors often have a high risk of recurrence despite initially successful treatment, it is important that those affected attend their follow-up appointments regularly.
The prognosis for new tumors is more favorable the sooner they are discovered. New brain tumors do not always immediately lead to symptoms that should warn the patient. Findings that require treatment are often discovered by chance during follow-up care.
However, if unusual pain is noticed outside of the follow-up checks, this is always a reason to see the doctor treating you as soon as possible. He can decide whether the next follow-up appointment should be brought forward in order to be able to rule out the possibility of new tumors forming in a timely manner.
You can do that yourself
A mixed glioma requires medical treatment in any case. The self-help measures focus on supporting medical therapy and alleviating the individual symptoms.
In the event of an epileptic seizure, first aid must be provided first. That means loosening clothing around your neck, moving dangerous objects out of reach, and calming the victim down as best you can. Bed rest and a bland diet can relieve nausea and vomiting. Headaches and tiredness are also best counteracted with rest. Sometimes it makes sense to go for a walk in the fresh air. The doctor will give the patient additional strategies that can be used to reduce the symptoms of a brain tumor. From there, the disease should be treated therapeutically. Talking to relatives, a psychologistor other people affected, fears can be addressed and thus a new perspective on life with the disease can be gained.
After the treatment, body and mind are often very exhausted. Through physiotherapy, a change in diet and pursuing hobbies and passions, those affected can recharge their batteries for a cancer-free life.