What is a brain meningioma? Prognosis of the disease

Meningioma of the brain is the primary tumor that grows from the cells of one of the meninges (arachnoid or arachnoid). In the overwhelming majority of cases, this tumor is benign. Can occur at any age, more common in female patients. The preferred location of the meningioma is the cranial cavity, but sometimes the tumor is found in the spinal canal. Why does a meningioma occur, how does it manifest itself, how it is diagnosed and treated, what promises the patient in the future? You will get the answers to all these questions by reading this article.

General information

Meningioma is a tumor of the arachnoid membrane of the brain or (rarely) the spinal cord (in the figure - arachnoid mater).

Meningioma is one of the most frequent tumors of intracranial localization. It accounts for more than 20% of all newly diagnosed brain tumors. The term was coined in 1922 by the American neurosurgeon Cushing. A tumor is a conglomerate of cells of different sizes from the arachnoid (arachnoid) envelope of the brain or spinal cord. Meningiomas are mostly separated from the surrounding brain tissue by a capsule. Forms most often occur spherical or horseshoe-shaped meningiomas, less often flat ones. Their dimensions vary from a few millimeters to knots 15 cm in diameter. Meningiomas are almost always associated with the dura mater and even adjacent bones. This means that the tumor is attached to them and even sprouts them right through. In those places where the meningioma is attached to the bone, the tumor stimulates the development of bone cells. As a result, a thickening of the bone tissue is formed, which can sometimes even be felt with your fingers. This symptom is very specific, because it occurs only with meningiomas.

In about 95% of cases, meningiomas are benign tumors. This concept means their relatively slow growth, separation from the surrounding tissue of the brain capsule, the absence of significant compression of the brain substance and a low percentage of recurrence. The remaining 5% of meningiomas are malignant. Malignant meningiomas are prone to rapid growth, infiltration of surrounding tissues and recurrence. Naturally, benign meningiomas have a better prognosis than malignant ones.

There are so-called multiple meningiomas. They account for about 2% of all cases newly diagnosed by meningiomas. "Multiple" - in this case means more than one tumor, identified simultaneously. Presumably, this situation occurs when initially there was a single meningioma, but not diagnosed, and then there was its local metastasis over the liquor spaces.

The prevalence of meningiomas is 7.7 cases per 10, 00 population. And here there is an interesting regularity: among them, at least some manifesting tumors account for 2 cases, and for asymptomatic cases - 5.7. It turns out that most of the meningiomas are detected by chance during a survey on a completely different occasion! Such statistics appeared due to the wide use at present of modern research methods (computer and magnetic resonance imaging).

What causes can lead to the development of meningitis?

It is impossible to answer this question unequivocally. There are only risk factors, the presence of which may be associated with the occurrence of meningiomas. They include:

• X-ray or radioactive radiation (especially the area of ​​the skull);
• genetic defects in the 22nd chromosome;
• female sex (probably due to the influence of female sex hormones, estrogens and progesterone);
• age is more than 45-50 years;
• the presence of type 2 neurofibromatosis.

Classification of meningiomas

The division of this variety of tumors is usually done according to several parameters: histological type, localization in the cranial cavity, and malignancy degree.

The histological type of meningioma is:

• typical (meningotiomatous, fibrotic, transitional, psammomatous, angiomatous, secretory, microcystic, with an abundance of lymphocytes, metaplastic);
• atypical;
• chordoid;
• clear cell;
• anaplastic;
• rhabdoid;
• papillary.

Typical meningiomas have the first degree of malignancy, that is, they are essentially benign; Atypical, chordoid and light-celled - 2nd degree of malignancy (more aggressive, more likely to relapse, have a worse prognosis than the first group); anaplastic, rhabdoid and papillary - grade 3 malignancy (with unfavorable prognosis). In general, the concept of "good quality" regarding additional formations inside the skull is very relative. After all, the cranium is not elastic and does not know how to stretch (except during the infancy, when the fontanels are not yet closed). And this means that with the appearance of plus-tissue in the cranial cavity, intracranial pressure invariably increases. And even if the meningioma is benign in terms of histological classification, but its dimensions are large, it will pose a threat to man in the same way as a malignant one.

The localization of meningiomas can be:

• convectional (that is, proceed from the outer surface of the brain adjacent to the bones of the skull, are not associated with the superior sagittal sinus and its lacunae). They can be frontal, parietal, temporal and occipital. They constitute 23% of the meningiomas of all localizations;
• prasagittal (meningiomas associated with the superior sagittal sinus and with a large sickle-shaped process). They account for about 30%;
• meningiomas of the anterior cranial fossa (20%);
• meningiomas of the middle cranial fossa (15%);
• meningiomas of the posterior cranial fossa (7%);
• meningiomas of the nerve of the cerebellum (amounting to 3%);
• meningiomas of the large occipital foramen (found in 1% of cases);
• meningiomas of rare localizations (intraventricular and others). They account for about 1%.

This division has its own meaning. Depending on the location of the meningioma, one or another type of treatment (surgical or radial) is planned.

Signs of meningitis

Meningiomas of small size occur asymptomatically and are found by chance during CT or MRI for a different pathology.

Strangely enough, to date, in most cases of primary detection of meningiomas, it turns out that they are asymptomatic, that is, they do not show themselves. And they are found out absolutely casually at performance of computer or magnetic resonance tomography concerning other disease. Of course, this is possible only at small tumor sizes, in the absence of compression of functionally important brain areas.

And yet it does not always happen. Often this variety of tumors manifests itself as small deviations in the state of health that the patient does not attach importance to. For example, the only symptom of meningioma can be a headache. But after all, not every person with a headache has a meningioma. The reasons for the headache are thousands. Therefore, it is wrong to regard each case of a headache in the context of a possible meningioma.

Meningiomas do not have any specific symptoms. Any signs that the patient may feel are not related to the type of tumor in the cranial cavity. They appear due to the presence of "excess" tissue in the cavity of the skull, compression of the tumor surrounding the brain substance and the development of edema of the brain tissue. Since meningiomas usually grow slowly, the symptoms do not progress rapidly, which means that the patient does not sound an alarm.

In general, the symptomatology of the meningioma depends on its location, size and growth rate. Among the signs that may indicate the presence of a meningioma, we can note the following:

• headache. They are often dull, aching, may be felt in a certain area of ​​the head or be diffuse. More often headaches are more pronounced in the night and morning hours. Sometimes the patient feels the bursting of the head from the inside;
• epileptic seizures. This symptom is specific for convective meningiomas. Epileptic seizures can be very diverse, but more often still there are generalized tonic-clonic seizures with loss of consciousness;
• focal symptoms. By "foci" refers to the development of any symptom due to compression of a strictly defined part of the brain. Thus, when the temporal region of the brain is compressed, right-handed speech may be broken in the right-handers, paresis and paralysis in the limbs may occur when the tumor is squeezed by the motor zones of the cerebral cortex. Perhaps the emergence of sensitivity disorders, visual impairment (reduced acuity or loss of visual fields), olfaction, omission eyelids, impaired movement of the eyeball, impaired control of the function of the pelvic organs (for example, urinary incontinence) and others;
• changes in the mental sphere. The appearance of this kind of symptoms is associated with the damage to the substance of the frontal lobes. Psycho-emotional signs are nonspecific, can have a different degree of severity;
• signs of increased intracranial pressure. It can be persistent headaches of a bursting nature, a feeling of pressure on the eyeballs from inside the cavity skull, attacks of nausea and vomiting, visual impairment (eye swelling of the optic disc). In advanced cases, even a violation of consciousness is possible.

I would like to emphasize once again the fact that none of the above symptoms is a sign of the presence of a meningioma. Each of them can only testify about some new growth growing in the cranial cavity (and that is not always the case). Therefore, to further clarify the diagnosis, further examination is necessary. And without additional methods of research here is indispensable.

Diagnostics

Currently, the most accurate methods of detecting meningiomas are computed tomography and magnetic resonance imaging. In this case, most often during the study, it may be necessary to introduce a contrast agent into the vascular channel (contrast enhancement). On CT and MRI images, meningiomas look very specific, which in 85-90% of cases allows you to correctly establish a diagnosis. To clarify the features of the blood supply to the tumor and clarify a number of points for the surgical treatment may need angiography. And in some cases, a tumor biopsy is possible to clarify the histological type of meningioma for treatment planning.

Methods of treatment of meningiomas

The most effective method of treating benign meningioma is surgical intervention.

As already mentioned above, in many respects the approach to the treatment of a meningioma is determined by its localization, size, rate of progression. In some cases (especially with regard to "accidentally" detected by meningiomas with no clinical symptoms), even expectant management is possible, that is, the lack of treatment as such. Meningioma can be small in size and grow very slowly. If the attending physician makes a decision about expectant management, then CT or MRI control over the tumor becomes mandatory, that is, a systematic repetition of these examinations, so as not to miss the moment when the tumor starts to increase.

Since meningiomas are usually benign, the most widely used for their treatment are surgical methods. That is, the tumor is simply removed. And the more radically the tumor is removed, the better the prognosis for the patient. Ideally, a neurosurgeon should strive to maximize the removal of tumor tissue. However, unfortunately, this is not always possible. After a tumor can be located in the functionally significant areas of the brain or simply not accessible to complete removal (for example, sprouts into the optic nerve). Neurosurgeons adhere to this principle regarding the removal of meningiomas: the surgical treatment performed should not increase the neurological deficit in the patient. Simply put, if after the operation the patient refuses a hand or a leg, which will make him deeply disabled, then there can not be any talk of total removal. Therefore, in each specific case, they try to find the golden mean: to remove the tumor as much as possible, and not to cause even greater harm to the patient.

The most radical is an operation in which it is possible to remove the entire tissue of the tumor, part of the dura mater in the place of the initial growth and the affected bone. In this case, the percentage of tumor recurrence approaches zero.

If the meningioma recurs with time, then a second operation may be necessary. According to statistics, the five-year survival rate of patients operated on for meningioma is 92%. The probability of relapse with a complete removal of a benign tumor over the next 15 years is 4%.

Another method of treatment of meningiomas is stereotactic radiosurgery. Stereotactic radiosurgical techniques are based on targeted irradiation of the meningioma tissue at various angles. At the same time, calculations are made so that only the tumor tissue is exposed to maximum irradiation, and the adjacent normal tissues are minimal. This method of treatment is used in those cases when the meningioma is located near vital brain structures, which the neurosurgeon can not get to. It is also possible to use stereotactic radiosurgery independently for small meningiomas (up to 3.5 cm in diameter). Sometimes surgical removal of a tumor is combined with radiosurgical techniques (in case of impossibility of radical tumor removal) or during recurrence after surgical treatment.

Standard radiotherapy is being used less and less often. After all, with this method of treatment, the rays destroy not only the tumor tissue, but also the adjacent healthy tissues.

Prognosis of the disease

What does the patient expect after the detection of meningioma? There is no unequivocal answer to this question. Benign meningiomas can be cured by radical tumor removal. They practically do not recur, after further surgery, no further treatment is required. In such cases, only CT or MRI monitoring is needed 2-3 months after surgery, then one year later after the operation, in the absence of signs of continued growth of the tumor - a year later, and then once every two years.

With meningiomas that can not be completely removed, things are more complicated. In most cases, they require combined treatment (surgery + stereotactic radiosurgery) followed by CT or MRI control. If signs of recurrence of a meningioma are found, a second operation or radiotherapy may be required.

Malignant meningiomas uniquely require combined treatment: both surgical removal of tumor tissue, and radiation therapy. CT and MRI monitoring in these cases is carried out much more often: 2 and 4 months after the operation, and then 1 time in 6 months for 5 years. If there is no relapse within this time interval, then CT or MRI of the brain can be performed once a year. Unfortunately, malignant forms of meningiomas relapse in 78% of cases during the first 5 years after the operation.

The frequency of occurrence of relapses is also affected by the localization of the tumor. Thus, meningiomas of the sphenoid bone (wings, bodies) also give a high percentage of continued growth - from 34 to 99%, and convective - only 3%. All these data are used in determining the tactics of treatment of a particular patient.

As you can see, a meningioma is a very multifaceted tumor. It may not affect the health of the patient at all, or may lead to his passing out of life. How the meningioma will behave depends on many factors, but primarily on its location, dimensions, histological type. Meningioma is not the final verdict. You can get rid of it. Just do not delay the visit to the doctor.

Neurosurgeon Reutov A. A. tells about a meningioma:

Briefly about meningiomas. Interview with neurosurgeon Reutov AA

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