meningioma

Meningioma: description

Meningiomas are tumors of the soft meninges. With a share of about 25 percent, they are among the most common neoplasms in the central nervous system. Meningitis usually affects adults around the age of fifteen. Only two percent of these tumors are diagnosed in children and adolescents. Women are affected twice as often as men.

Most meningoma is benign and grows slowly over several years. It is rarely malignant and grows faster. The tumor is usually well separated from the adjacent brain structures and does not grow into other tissues. It can grow flat or nodular and sometimes calcify. Often the skull bone is thickened above the tumor.

In more than 90 percent of cases, a meningioma grows in the skull (intracranial). There it is usually found on the meninges, which separates the two halves of the brain. It grows less often in the sphenoid sinus or in several places. It can also form on the meninges of the spinal cord in the spinal canal. Depending on where the tumor settles, it can cause different ailments.

Meningioma classification

The World Health Organization (WHO) divides meningeomes into three different degrees of severity:

• Grade I: meningioma
• Grade II: Atypical meningioma
• Grade III: Anaplastic meningioma

Both the treatment and the prognosis are influenced by this classification.

Meningoma Grade I accounts for over 85 percent of all meningiomas. It is benign and can usually be completely removed by surgery.

About ten percent of meningiomas are atypical (grade II). They can grow a little faster and often return after a successful operation (recurrence).

The anaplastic meningioma (grade III) is rare with a proportion of two to three percent. It is classified as malignant and can spread to distant organs (metastasis formation).

Meningioma: symptoms

It sometimes takes several years for a meningioma to cause symptoms. This is because the tumor usually grows very slowly. Only when it displaces neighboring structures such as nerves or important brain regions, the first signs of disease appear.

Meningioma symptoms are rather nonspecific and can also occur in other diseases. If the tumor is located in the movement center, individual muscle groups, for example, on the arms or legs can be paralyzed. If, on the other hand, it grows in the olfactory groove, odor disorders occur. Some sufferers gradually smell less and less over a longer period of time, which many do not even notice.

A meningioma can also irritate the meninges and trigger a seizure. Some patients suffer from headaches. In general, changes in nature, fatigue, visual and speech problems are also conceivable. Very rarely, the malignant cells grow into the bones and overlying scalp. Then you can feel it under certain circumstances.

Often, a meningioma grows so slowly that the brain can adapt to this new formation and no complaints occur. Then it is sometimes discovered accidentally during an imaging examination.

Meningioma: causes and risk factors

A meningioma forms from the capillaries of the soft meninges. The soft meninges cover the brain. On the outside, the hard meninges and the skull join.

A meningioma develops when one of the cover cells begins to grow uncontrollably. Why this happens is not fully understood. However, people at higher risk of the disease have had to be irradiated for another malignant disease. In addition, the hereditary disorder neurofibromatosis type 2 is associated with the formation of a meningioma. Not infrequently, there are even multiple meningiomas in this disease.

Meningioma: examinations and diagnosis

If a meningioma causes symptoms, a specialist in neuropathy (neurologist) is the right person to contact. He first inquires about the symptoms and their time course as well as about possible pre- and underlying diseases (collection of the medical history = anamnesis). As part of a neurological examination, he examines individual nerves, the sense of smell and the eyes. Thereafter, further investigations follow.

So images of the head or spinal canal must be made. First, a computed tomography (CT) is usually performed. Some patients receive a contrast agent in a vein for the examination. In CT, calcified structures and swelling of the surrounding brain tissue can be well recognized. The contrast agent accumulates in the meningioma so that it becomes visible in the image as a light structure. With a magnetic resonance examination (magnetic resonance imaging, MRI), the tumor can also be displayed very well. Both procedures allow the physician to determine the exact size and location of the neoplasm.

An X-ray examination of the blood vessels (angiography) in the head can also be enlightening. This will help physicians find out which vessels are associated with the tumor and need to be considered in a subsequent surgery. In addition, it can be seen in this investigation, whether the tumor relocates certain vessels and thereby limits blood flow.

Meningioma: treatment

Not every meningioma needs to be treated immediately. If the tumor is small and does not cause discomfort, it can also be observed first. For this purpose, the radiologist periodically prepares imaging by means of CT or MRI and checks whether the tumor is growing.

When a meningioma has to be treated depends on various factors. It depends on where the tumor sits, how tall it is and how aggressively it grows. In addition, the physical condition of the person concerned is taken into account.

Meningioma operation

Surgery is the most appropriate form of therapy for this type of brain tumor. The surgeon opens the skull bone with a saw and tries to remove the tumor as completely as possible. If the tumor is supplied by many or larger vessels, they can be closed before surgery (embolization). This avoids major blood loss during surgery. Since many important structures are located next to each other in the most confined space in the brain, meningioma surgery is sometimes difficult and involves certain risks. It can hurt nerves, blood vessels and other brain structures, which can leave lasting damage. Sometimes, to prevent this, the tumor can not be completely removed. He is then destroyed by a subsequent radiotherapy.

Meningioma: radiotherapy

The tumor should be irradiated if it can not be completely removed by surgery or if malignant cells are present in the examined tissue. This improves the prognosis of the patient. In certain cases, meningiomas are also irradiated without prior surgery.

Meningioma: disease course and prognosis

The course of the disease and the prognosis depend very much on the WHO grade of the tumor and whether it can be completely removed. After a complete surgical removal, the tumor returns in about every ten patients within ten years, after incomplete surgery in more than one in two. This number can be almost halved by radiotherapy after the procedure.

A malignant meningioma has a much worse prognosis than benign forms. Despite surgery and radiotherapy, it returns in up to 80 percent of cases. Therefore, the treatment should be successful in a meningioma be checked regularly.