brain tumor

Brain Tumor: Description

The term brain tumor refers to any benign and malignant tumor within the skull. Brain tumors are relatively rare compared to bowel, lung, breast or other cancers. In 2010, according to cancer registry data of the Robert Koch Institute, approximately 2,900 women and 3,800 men in Germany contracted a brain tumor. In both genders, most illnesses were recorded between the ages of 70 and 75 years. About 100 females and 200 males were under 20 years old.

Brain tumor is relatively common in children compared to other cancers. According to the Childhood Cancer Registry, about a quarter of childhood cancers are due to tumors of the central nervous system.

Brain tumor is not the same brain tumor. First, there are as mentioned both benign and malignant brain tumor forms (“brain cancer”). In addition, a distinction is made between primary and secondary brain tumors: primary brain tumors

The primary is a brain tumor that develops directly from cells of the brain or the meninges. Such tumors are also referred to as brain tumors.

Tumors that originate from a cranial nerve are often counted among the primary brain tumors. The cranial nerves are to a large extent in the skull, but are not attributed to the central nervous system (CNS: brain and spinal cord), but the peripheral nervous system. If a tumor in the head of a cranial nerve, it is therefore actually a neoplasm of the peripheral nervous system.

The primary brain tumors are subdivided according to different criteria. The World Health Organization (WHO) divides the individual tumors according to which tissue they are derived from and to what extent the brain tumor is malignant or benign. This distinction influences both brain tumor treatment and prognosis. Interestingly, only a small proportion of brain tumors are derived from nerve cells (neurons). More than every second primary brain tumor develops from the supporting tissue of the brain and thus belongs to the group of gliomas. The following table gives an overview of the most important brain tumors:

gliomas	They are derived from the supporting cells of the CNS. These include, for example, astrocytoma, oligodendroglioma and glioblastoma.
Ependyom	This brain tumor is formed by cells that line the inner brain chambers.
medulloblastoma	The medulloblastoma is formed in the cerebellum. It is the most important brain tumor in children.
neurinoma	This tumor is based on cranial nerves. He is also called Schwannom.
meningioma	This brain tumor develops from the meninges.
CNS lymphoma	CNS lymphoma forms from a cell group of white blood cells.
Germ cell tumors	Germ cell tumors include germinoma and choriocarcinoma.
Brain tumor of the Sellaregion	These tumors are found in a certain place in the brain, the sella turcica. This is usually the pituitary gland. They include the pituitary adenoma and the craniopharyngioma.

In each age group, individual brain tumors are more common than others. Among the primary brain tumors, gliomas, meningiomas, and pituitary tumors are most common in adults. If a brain tumor occurs in children, it is usually a medulloblastoma or a glioma.

Secondary brain tumors

Much more common than a primary brain tumor are secondary brain tumors. They arise when cells from other organ tumors (for example, lung cancer, skin cancer, breast cancer) enter the brain and form a daughter tumor here. These are therefore brain metastases. They are not considered by some professionals as a “true” brain tumor.

With the brain metastases one differentiates between removals in the brain tissue (parenchyma metastases) and those in the meninges (meningeosis carcinomatosa).

Brain tumor: symptoms

You can read all about possible signs of a brain tumor in the article Brain Tumor – Symptoms.

Brain Tumor: Causes and Risk Factors

So far, it is largely unknown why a primary brain tumor forms. For most people affected, no triggering factor can be found. If no brain tumor causes are known, experts also speak of a sporadic brain tumor.

In contrast, there is also a hereditary brain tumor. It may be caused by certain hereditary diseases such as neurofibromatosis, tuberous sclerosis, Von Hippel-Lindau syndrome or Li-Fraumeni syndrome. However, these diseases are extremely rare. Only a small proportion of brain tumors can be traced back to one of these clinical pictures.

CNS lymphomas are more likely to develop in patients with a severely weakened immune system, such as those due to HIV or the use of immunosuppressants to prevent rejection after organ transplantation.

Otherwise, the only known risk factor for a brain tumor is the radiation of the nervous system. It is used in life-threatening conditions such as acute leukemia. Overall, very few people develop a brain tumor after brain irradiation. Incidentally, ordinary X-ray examinations do not cause brain tumors.

Secondary brain tumors, ie brain metastases, form when there is cancer in the body. Therefore, if there are risk factors for a specific cancer, the risk of brain metastases is also increased. However, not every malignant tumor spreads to the brain.

brain metastases

You can read more about this topic in the article Brain Metastases.

Brain tumor: examinations and diagnosis

The right contact person for a brain tumor is a specialist in neurology (neurologist). In order to be able to carry out the correct diagnostic steps, he / she must make an accurate medical history (anamnesis). In addition he asks for your exact complaints, possible pre-existing illnesses and medical treatments. Possible questions are for example:

• Do you suffer from new headaches (especially at night and in the morning)?
• Do you have a headache when lying down?
• Do you use conventional headache medication?
• Do you suffer from nausea and vomiting (especially in the morning)?
• Do you have blurred vision?
• Did you have a seizure? Did one half of the body jump involuntarily?
• Did you have or have problems moving or coordinating a body part?
• Did you have or have problems speaking?
• Do you notice restrictions when you concentrate, memorize, or understand something?
• Have any new hormonal disorders occurred?
• Do your relatives or friends think that your personality has changed?

After that, the doctor performs a neurological examination. He tests muscular reflexes, muscle strength and coordination. He also checks if the cranial nerves are functioning properly, for example by asking you to frown, or by looking you in the eyes to test the pupil reflex. He also checks your field of vision and looks at the fundus with an examination light.

Thereafter, further examinations may follow such as computed tomography (CT), magnetic resonance imaging (MRI), electroencephalography (EEG) and nerve water examination. If these examinations indicate a brain tumor, the removal of a tissue sample (biopsy) may be necessary for a more detailed investigation.

If your neurologist suspects that your symptoms are caused by brain metastases, the causative cancer must be diagnosed. Depending on the suspicion, you may be referred to another specialist (such as a gynecologist or gastroenterologist).

CT and MRI

In CT, the patient is placed on a couch in the examination tube, where the brain is X-rayed. On the computer, one can then recognize the brain structures on individual sectional images. With this procedure one can recognize especially bleeding and calcifications well.

In recent years, an MRI is increasingly made in suspected brain cancer. This examination also takes place in a test tube. It takes longer than a CT, but dispenses with X-rays. Instead, images of the body are made using magnetic fields and electromagnetic waves. The presentation is often even more detailed than in CT.

Sometimes both methods are performed sequentially. Both examinations are not painful. The narrow tube and the high noise level are perceived by some patients as unpleasant.

Measurement of electrical brain waves (EEG)

In a brain tumor, the electrical currents in the brain may be altered. An electroencephalogram (EEG) recording these currents can be very enlightening. Small metal electrodes are attached to the scalp and connected with cables to a special measuring device. Now, the brain waves can be derived in peace, in sleep or under light stimuli. Based on the results, a brain tumor, for example, can be distinguished from a seizure disorder. In addition, one can often use EEG to determine the origin of a brain change. This procedure is neither painful nor harmful and therefore particularly popular for the study of children.

Nerve water examination (CSF)

To exclude altered brain water pressure (cerebrospinal fluid) or meningitis, a nerve water puncture may be necessary. In addition, one can detect in the nerve water by a brain tumor modified cells.

The patient usually receives a tranquilizer or light sleep aid prior to this examination. In children, a general anesthetic is usually performed. Then first the lumbar area on the back is disinfected and covered with sterile towels. So that the patient has no pain during the puncture, a local anesthetic is first injected under the skin. Subsequently, the doctor can advance a hollow needle into a liquor reservoir in the spinal canal. So he can determine the CSF pressure and take some CSF for a laboratory examination.

The spinal cord can not be injured in this examination, because a point below the spinal cord end is chosen as the puncture site. Most people find the examination uncomfortable but bearable, especially as the CSF usually takes only a few minutes.

Taking a tissue sample

To classify a brain tumor, a tissue sample must be taken and examined under the microscope. This can be done either by an open brain tumor operation or a stereotactic surgical technique.

In open brain tumor surgery, the patient is placed under general anesthesia. The skullcap is opened, and the tumor structures are visited. This procedure is usually chosen when the brain tumor is to be completely removed in the same operation. Then the entire tumor tissue can be examined under the microscope. Of the result often depends on the further treatment.

Stereotactic surgery, on the other hand, is almost always performed under local anesthesia, so that the patient does not experience any pain. His head is fixed in a scaffold for sampling. An imaging procedure determines exactly where the tumor lies in the head. At a suitable place then a small hole in the skull is drilled (Trepanation), over which the operation tools can be introduced: The biopsy forceps can be led computer-controlled to the brain tumor and purposefully remove a tissue sample.

Brain tumor: treatment

Not every brain tumor is treated the same. Basically, you can operate on a brain tumor, irradiate or perform chemotherapy. But these three options can be performed in very different ways or even combined with each other.

Which brain tumor treatment is suitable in a particular case depends on the type of tissue, the cell change and special molecular biological characteristics. Of course, it also takes into account how advanced the disease is and what wishes the person expresses. Not all options are available for every patient, but there are usually alternative treatments.

Brain tumor: surgery

A brain tumor operation can have different goals. Some brain tumors can be completely removed by surgery. In other cases, the tumor can only be resized in one operation. However, this can sometimes relieve the symptoms and improve the prognosis, because the tumor reduction creates better conditions for subsequent treatments (radiotherapy, chemotherapy).

An operative procedure in brain tumor patients may also have the goal to compensate for a tumor-related outflow disorder of the nerve water. Because the CSF can not flow away undisturbed, the pressure in the brain increases, which causes serious discomfort. In an operation, for example, a shunt can be implanted, which dissipates the brain water, for example, into the abdomen.

In most cases, open brain tumor surgery is performed under general anesthesia: the head is fixed on a metal framework. After the skin is severed, the skull bone can be sawn and the hard meninges opened. The brain tumor is visited and operated under a special microscope. Some patients receive a fluorescent agent that is taken up by the brain tumor before surgery. During the operation, the tumor then shines under a special light. As a result, it can be better distinguished from the surrounding healthy tissue.

If the tumor is located near important brain centers, these are monitored by special examinations. Thus, for example, sensitive and motor functions or the Hörbahn be protected. The language center can only be monitored if the operation is performed under local anesthesia. Sometimes the operation is interrupted to check the operation success by means of imaging (CT, MRI).

After surgery, bleeding is stopped and the wound closed. The patient is initially transferred to a monitoring station until his condition is stable. In the further course, imaging is usually initiated again in order to check the result of the operation. In addition, patients usually receive a cortisone preparation for a few days after surgery. It should prevent the brain from swelling up.

Brain Tumor: Irradiation

Some brain tumors are treated exclusively with radiotherapy. For others, this is just one of several treatments.

When irradiated brain tumor cells are destroyed, but adjacent healthy cells are spared as possible. In general, it is not possible to record only the brain tumor. Thanks to good technical possibilities, it can be very well calculated with a previous imaging, which area should be irradiated. The irradiation takes place in several individual sessions, because this improves the result. In order not to have to redefine the tumor area at each session, individual face masks are made. Thus, the patient’s head can be brought exactly in the same position each time for the irradiation.

Side effects can occur with radiotherapy. For example, the skin may redden over the irradiated area. Headaches and nausea also occur. The doctor will tell you about possible side effects before radiotherapy and tell you how to deal with them.

Brain Tumor: Chemotherapy

Special cancer drugs (chemotherapeutic agents) are used to kill brain tumor cells or stop their reproduction. If the chemotherapy is done before surgery (to make the tumor smaller), it is called neoadjuvant chemotherapy. On the other hand, if it adheres to the surgical brain tumor removal (to kill residual tumor cells), professionals call it adjuvant.

Different drugs are suitable for the different types of brain tumors. Some brain tumors do not even respond to chemotherapy and must therefore be treated with another therapy.

Unlike other cancers, in a brain tumor chemotherapeutics first have to cross the blood-brain barrier to reach their destination. In individual cases, the chemotherapeutic agents can also be injected directly into the spinal canal. They then enter the brain with the nerve water.

As with radiotherapy, chemotherapy also detects healthy cells. This can cause certain side effects, such as a disorder of blood formation. The typical side effects of the drugs used are discussed in a doctor’s consultation before treatment.

Brain Tumor: Supportive Therapy

The term “supportive therapy” summarizes all measures that support the patient during his illness. It does not fight the tumor directly, but only the discomfort it causes or the treatment (such as chemotherapy). For example, headache, increased intracranial pressure, vomiting, nausea, pain, infections or blood changes can be treated with medication. A psycho-oncological care can also be part of the supportive therapy: It should support patients and their relatives in dealing with the serious illness.

Brain tumor: disease course and prognosis

Every brain tumor has a different prognosis. The course of the disease and the chance of cerebral tumor healing depend very much on how the tissue of the tumor is built up and how fast it grows. As an indication for physicians and patients, WHO has developed a classification of tumors according to their severity. In total, there are four severity levels, which are mainly defined by the tissue examination:

• Grade I: Benign brain tumor with slow growth and very good prognosis
• Grade II: Benign brain tumor, but can turn into a malignant
• Grade III: Malignant brain tumor
• Grade IV: Very malignant brain tumor with rapid growth and poor prognosis

This classification not only serves to estimate the personal brain tumor healing chances. It also depends on how a brain tumor is treated. Thus, a first-degree brain tumor can usually be cured by a brain tumor operation. A second-degree brain tumor can recur after surgery. For WHO grade III or IV, the brain tumorHealing chances so bad that after surgery in each case a radiation and / or chemotherapy is recommended.