What is a meningioma?
A meningioma (or meningioma) is a tumour that originates in the meninges and is usually benign. Although the tumour does not grow into the brain tissue, it gradually displaces it. Because meningiomas grow quite slowly, they can usually be easily removed by surgery. Meningiomas are the most common type of tumour in the central nervous system. The likelihood of developing a meningioma increases with age, and women are about twice as likely to develop a meningioma as men.
How does a meningioma develop?
A meningioma develops in the meninges or the spinal cord. If the meninges degenerate, a meningioma can develop. Doctors are still unclear about the exact causes of this cell degeneration. However, they assume that a genetic predisposition as well as ionising radiation can contribute to the formation of a meningioma. A meningioma gradually displaces the brain, but does not grow directly into the brain.
What are the different types of meningioma?
The World Health Organisation (WHO) distinguishes between the following three grades of meningioma:
- Grade I: simple, non-malignant (benign) meningioma, which is the most common with between 85 and 74 per cent and occurs three times more often in women than in men. Since the simple meningioma can often be completely removed by surgery, its prognosis is good.
- Grade II: atypical meningioma, which occurs between 23 and 10 per cent of all cases and affects men on average more often than women. Since the atypical meningioma grows more and can recur even after surgery (recurrence), this type of tumour must be checked frequently.
- Grade III: analplastic or malignant (malignant) meningioma, which develops between 4 and 2 per cent of all cases, but occurs more often in men than in women. The anaplastic meningioma can spread metastases and thus also affect other organ structures.
What symptoms does a meningioma cause?
The specific symptoms of a meningioma depend on the location as well as the size of the tumour. Because meningiomas usually grow rather slowly, they cause hardly any symptoms over a certain period of time. Only when they cause symptoms because they press on the surrounding structures can they cause non-specific symptoms such as headaches, dizziness to the point of paralysis, seizures and/or loss of the sense of smell. In these cases, the meningioma must be treated urgently.
Furthermore, meningiomas can cause the following non-specific symptoms:
- Vomiting,
- Visual disturbances, which may be accompanied by paralysis of the eye muscle,
- Breathing, sensory and/or consciousness disorders,
- Increase in blood pressure with a simultaneous drop in heart rate,
- Discomfort when going to the toilet.
How is a meningioma diagnosed?
Because meningiomas often grow without symptoms, they are usually discovered by chance during a computer tomography (CT) or magnetic resonance imaging (MRI). If a meningioma is suspected, the neurologist can also perform an angiography. This is a radiological examination that shows which blood vessels have been displaced or squeezed by the tumour and which blood vessels supply the tumour.
Alternatively, a magnetic resonance spectroscopy (MRS) or a blood flow measurement of the brain can help to determine the exact location of the tumour. In addition, a biopsy can be performed to confirm the diagnosis of a specific meningioma.
How is a meningioma treated?
First and foremost, the neurologist will try to surgically remove the meningioma completely, including the adjacent meninges and the bone affected by the tumour. At the same time, the neurologist must ensure that the surrounding structures are spared as much as possible, which is why the operation is planned in detail before the intervention. In addition to the exact location of the tumour, it is also important to find an access point to surgically remove the meningioma.
Since the complete removal of the meningioma is not always possible, for example due to the localisation to delicate vascular-nerve structures, radiotherapeutic or radiosurgical treatment can be performed as an alternative. In general, a meningioma in the area of the lateral cranial dome can usually be removed surgically more easily than a meningioma at the base of the skull or in the midline.
If the tumour is small and/or asymptomatic, it may be possible to monitor it initially at regular intervals by means of a Ct or an MRI.
Aftercare of a meningioma
In principle, rehabilitation treatment is recommended after a meningioma, which can take place either as an outpatient or as an inpatient. If it is a benign tumour that could be removed surgically, doctors will usually order neurological rehabilitation. After the removal of a malignant meningioma, on the other hand, oncological rehab is also an option in addition to neurological rehab.
While neurological rehabilitation focuses on the impairments caused by the brain tumour (such as difficulties in motor function, speech or balance disorders), oncological rehabilitation aims to strengthen the patient both physically and psychologically. Alternatively, neuro-oncological rehabilitation combines both approaches.
What is the prognosis for a meningioma?
A meningioma usually grows very slowly, so that the tumour can often be removed surgically, including the adjacent meninges and bone. This is especially true for first-degree meningiomas. This means that the chances of survival are relatively good, as the risk of the tumour returning is also rather low.
In the case of second-degree meningiomas (grade II), there are benign cases that are free of recurrence in the long term after successful surgery. However, there can also be more unfavourable courses, which tend to have high recurrences despite multiple treatments. Scientists are therefore trying to identify molecular markers in studies in order to better assess the prognosis after an operation and to better adapt the treatment methods to the patient.
If it is a third-degree meningioma, its prospects for complete cure are rather low. However, the 5-year survival rate after diagnosis is 90 percent.