Dr. Schwarz studied medicine in Wurzburg, where she also completed her doctorate. After very varied tasks during the medical practical training (PJ) u.a. in internal medicine and surgery, she is now a specialist in radiology.
Dr. Monique Amey-ozel studied biology at the University of Bonn and completed her doctorate in neuroscience. She spent several years in research and as a lecturer u.a. active in the subject of anatomy at medical training institutions. She advised physicians on various indications as a pharmaceutical sales representative and is now a medical editor responsible for writing medical texts for both specialists and interested laypersons.
A Brain tumor Is a disease of the central nervous system with a cause that is usually unexplained. People of all ages develop them, with more severe cases occurring predominantly in childhood or in the elderly. There are numerous types of brain tumor – benign and malignant. Their treatment and prognosis vary greatly. Treatment options include surgery, radiation and/or chemotherapy. Here you can read everything important about brain tumor.
- Causes: In primary brain tumors, the cause is usually unclear. Secondary brain tumors (brain metastases) usually underlie other cancers. In some cases, the trigger is a hereditary disease such as neurofibromatosis or tuberous sclerosis.
- Diagnosis and examination: The physician performs physical examinations and takes a detailed medical history. Other diagnostic procedures include computed tomography (CT), magnetic resonance imaging (MRI), electroencephalography (EEG), tissue examination (biopsy), and a nerve fluid and blood test.
- Treatment: Surgery, radiation and/or chemotherapy, concomitant psychotherapy
- course and prognosis: The prognosis depends strongly on the severity of the tumor and the health of the affected person. The higher the severity and the later treatment begins, the worse the prognosis.
What is a brain tumor?
The term brain tumor or brain tumor refers to any benign or malignant growth within the skull. Compared to colon, lung, breast, or other cancers, brain tumors are rare. In 2016, according to cancer registry data from the Robert Koch Institute, approximately 3.460 women and 3.970 men in Germany developed a brain tumor. In both sexes, most diseases were diagnosed between the ages of 70. and 84. year of life. Experts believe that the number will continue to rise and expect about 8 in the future.000 new cases per year.
Compared to other cancers, a brain tumor is the second most common type of tumor in children. According to the pediatric cancer registry, one in 1.400 children under the age of 18 are affected, which represents about a quarter of tumor cases in children. Both malignant and benign forms occur, although benign tumors are less well recorded. Overall, boys are 20 percent more likely to develop the disease than girls.
However, not all brain tumors are the same. First, a distinction is made between primary and secondary brain tumors. Among the Primary brain tumors there are both benign (benign) and malignant (malignant) forms ("brain cancer"), while Secondary brain tumors are always malignant.
Primary brain tumors
A primary brain tumor is one that develops directly from cells of the brain substance or meninges. Such tumors are also referred to by physicians as brain tumors.
Primary brain tumors often include those that originate from a cranial nerve. The cranial nerves originate directly from the brain and are therefore partly located in the skull. Nevertheless, they do not belong to the central nervous system (CNS: brain and spinal cord), but to the peripheral nervous system (PNS). Therefore, if a tumor in the head originates from a cranial nerve, it is strictly speaking a neoplasm of the peripheral nervous system.
The type of brain tumor that affects peripheral nerves includes, for example, acoustic neuroma. In this case, the tumor forms on the auditory and vestibular nerve (= eighth cranial nerve), which impairs hearing and the sense of balance.
Primary brain tumors are further subdivided according to various criteria. The World Health Organization (WHO) classifies individual tumors according to the tissue from which they originate and the extent to which the brain tumor is malignant or benign. This distinction affects both the treatment and prognosis of a brain tumor.
Interestingly, only a small part of brain tumors originate 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 primary brain tumors:
Gliomas originate from the supporting cells of the CNS. These include, for example, astrocytoma, oligodendroglioma and glioblastoma.
This brain tumor forms from cells lining the inner chambers of the brain.
Medulloblastoma forms in the cerebellum. It is the most important brain tumor in children.
This tumor originates from cranial nerves. It is also called schwannoma.
This brain tumor develops from the meninges.
CNS lymphoma forms from a group of cells in white blood cells.
Germ cell tumors include germinoma and chorionic carcinoma.
Brain tumor of the sellar region
These tumors are found in a specific location in the brain, the sella turcica. This is where the pituitary gland is normally located. These include pituitary adenoma and craniopharyngeoma.
In each age group, individual brain tumors occur more frequently than others. Among primary brain tumors, gliomas, meningiomas and pituitary tumors are the most common in adults. If a brain tumor occurs in children, it is usually a medulloblastoma or a glioma.
A neuroblastoma is a so-called embryonal brain tumor, which occurs mainly in infants and young children. Neuroblastoma develops from certain nerve cells of the autonomic (vegetative) nervous system, which are found in numerous places in the body, for example next to the spine and in the adrenal gland.
Secondary brain tumors
In addition to primary brain tumors, secondary brain tumors are about equally common. They develop when cells from other organ tumors (for example, lung cancer, skin cancer, breast cancer) reach the brain and form a daughter tumor here. These are therefore Brain metastases. Some specialists do not consider these to be "real" brain tumors at all.
In the case of brain metastases, a distinction is made between metastases in the brain tissue (parenchymal metastases) and those in the meninges (meningeosis carcinomatosa).
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Signs of a brain tumor
Read everything important about possible signs of a brain tumor in the article Brain Tumor – Symptoms.
What causes brain tumors?
It is as yet largely unknown why a primary brain tumor forms. No trigger can be found in most affected people. If no causes are known, experts also speak of a sporadic brain tumor.
In contrast, there are brain tumors that are genetic and hereditary. They occur in 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 percentage of brain tumors can be attributed to one of these clinical pictures.
CNS lymphomas develop more often in patients with a severely weakened immune system, for example, due to HIV or when the immune system is suppressed by special drugs (immunosuppressants). Such treatment is usually used to prevent rejection after organ transplantation.
Otherwise, the only known risk factor for a brain tumor so far is radiation to the nervous system. Doctors use them, for example, in the case of life-threatening diseases such as acute leukemia. Overall, very few people develop a brain tumor after brain radiation treatment. Ordinary X-ray examinations do not usually cause a brain tumor.
Secondary brain tumors, that is Brain metastases, usually form when there is cancer elsewhere in the body. If risk factors for a certain cancer are present, the risk of brain metastases is often increased as well. However, not every malignant tumor spreads to the brain.
You can read more about this topic in the article Brain metastases.
How is a brain tumor diagnosed and examined??
The right contact person in case of a brain tumor is a specialist in neurology (neurologist). In the course of the diagnosis he precisely collects your medical history (anamnesis). In addition, he asks about your exact complaints, any previous illnesses and medical treatments. So possible questions include:
- Do you suffer from new types of headaches (especially at night and in the morning)??
- Do headaches increase when lying down?
- Do conventional headache medications help?
- Suffer from nausea and vomiting (especially in the morning)?
- Do you have visual disturbances?
- Have you experienced any seizures? Has one half of the body twitched involuntarily?
- Have you had or are you having trouble moving or coordinating any part of your body?
- Have you had or do you have problems speaking?
- Do you notice limitations when trying to concentrate, memorize, or understand something?
- Have you experienced any new hormonal disturbances?
- Do your relatives or friends think that your personality has changed??
After that, the doctor performs a neurological examination. He tests muscle reflexes, muscle strength and coordination. He also checks whether the cranial nerves are functioning properly, for example by asking you to frown or by shining a light into your eyes. In this way he tests the pupillary reflex. He or she will also check your visual field and use an exam light to look at the back of your eye.
This is often followed by further examinations such as computed tomography (CT), magnetic resonance imaging (MRI), electroencephalography (EEG) and neural fluid testing. If these examinations indicate a brain tumor, the doctor will then take a tissue sample (biopsy) to classify the previous results in more detail.
A blood test often also provides information about whether or not a brain tumor is present. The doctor looks for so-called tumor markers – substances secreted by tumor cells – in the blood tests. Gene changes (gene anomalies) can also be determined in this way.
If your neurologist suspects that brain metastases are causing your symptoms, the causative cancer must be diagnosed. Depending on your suspicions, your doctor may refer you to another specialist (such as a gynecologist or gastroenterologist).
CT and MRI
During CT, the patient lies supine on a couch that moves into an examination tube. The brain is examined with X-rays. On the computer, the brain structures and especially bleedings and calcifications in them can be identified on individual cross-sectional images.
For most CT scans, patients are injected with a contrast medium in the vein in their arm, which makes it easier to see the blood vessels and the tumors with their correspondingly strong blood supply. As a rule, these contrast media are well tolerated. Affected people excrete it again in their urine after some time.
In recent years, an MRI has been performed more and more frequently in cases of suspected brain tumors. This examination is also performed in an examination tube. It takes longer than a CT scan, but does not use X-rays. Instead, the images of the body are created by magnetic fields and electromagnetic waves flowing through it. The representation is often even more detailed than with CT. As with CT, the person undergoing MRI must remain very still and should not move as much as possible.
Sometimes it is necessary and helpful to perform both procedures consecutively. Both examinations are not painful. However, some patients perceive the tube and the high noise level as unpleasant.
Measurement of electrical brain waves (EEG)
A brain tumor often alters the electrical currents in the brain. An electroencephalogram (EEG), which records these currents, provides revealing information in this context. For this purpose, the doctor attaches small metal electrodes to the scalp, which are connected with cables to a special measuring device. The brain waves are derived, for example, at rest, during sleep or under light stimuli.
The results can be used, for example, to distinguish a brain tumor from a seizure disorder. In addition, it is often possible to determine the origin of a brain change by means of EEG. This procedure is neither painful nor harmful and therefore particularly suitable for the examination of children.
Nerve fluid examination (CSF puncture)
In order to exclude a change in cerebrospinal fluid pressure (CSF pressure) or meningitis, the physician sometimes performs a nerve fluid puncture in the area of the loin (lumbar puncture). In addition, cells altered by a brain tumor can be detected in the cerebrospinal fluid.
The patient is usually given a sedative or light sleeping pill before this examination. Children usually receive general anesthesia. The doctor then disinfects the lumbar area on the back and covers the area with sterile cloths.
To ensure that the patient does not experience any pain during the puncture, the doctor first numbs the area with an anesthetic that he injects under the skin. The doctor then inserts a hollow needle into a cerebrospinal fluid reservoir in the spinal canal. In this way, he determines the CSF pressure and removes some CSF for laboratory testing.
The risk of injury to the spinal cord is very low with this examination because the puncture site is below the end of the spinal cord. Most people find the examination unpleasant but bearable, especially since the CSF puncture usually takes only a few minutes to perform.
Taking a tissue sample
To classify a brain tumor more precisely, the doctor takes a tissue sample and examines it under the microscope. This is done either by open surgery or a stereotactic surgical technique.
In open surgery, the patient receives general anesthesia. The skullcap is opened in a certain area so that the tumor structures are accessible to the surgeon. The doctor usually chooses this procedure if he wants to remove the brain tumor completely in the same operation. The entire tumor tissue is then examined under the microscope. Further treatment often depends on the result.
Stereotactic surgery, on the other hand, is almost always performed under local anesthesia, so that the patient does not feel any pain. The patient’s head is immobilized during specimen collection. The physician uses an imaging procedure to determine exactly where the tumor is located in the head. A small hole is then drilled in the skull at a suitable location (trepanation), through which the surgical tools are inserted. As a rule, the movement of the biopsy forceps is computer-controlled and therefore very precise, which makes targeted sampling possible.
How a brain tumor is treated?
Every brain tumor requires individual treatment. In principle, it is possible to operate on a brain tumor, to irradiate it or to give it chemotherapy. These three options are adapted to each tumor and differ in the way they are performed or combined.
Which brain tumor treatment is appropriate in an individual case depends on the type of tissue, cell changes and molecular biological characteristics. Of course, it must also be taken into account how advanced the disease is and what wishes the patient expresses. Not all treatment options are suitable for every patient, but there are usually alternative treatment measures available.
Brain tumor surgery often has several goals. One goal is usually either to remove the brain tumor completely or at least to reduce its size. This can alleviate symptoms and improve prognosis. Even a tumor reduction creates better conditions for subsequent treatments (radiation, chemotherapy).
Surgical intervention in brain tumor patients is sometimes also aimed at compensating for a tumor-induced outflow disturbance of the neural fluid. If the cerebrospinal fluid (CSF) does not drain off undisturbed, the pressure in the brain increases, which causes serious problems. In one operation, for example, the doctor implants a shunt that drains the cerebrospinal fluid into the abdomen.
Most often, the doctor performs an open surgery under general anesthesia: The head is fixed in this case. After the skin is cut, the surgeon opens the skull bone and the underlying hard meninges. Brain tumor surgery is performed with the help of a special microscope. Some patients are given a fluorescent agent before surgery to absorb the cells of the brain tumor. During the operation, the tumor then shines under a special light. This makes it easier to distinguish it from the surrounding healthy tissue.
If the tumor is located near important brain centers, the doctor monitors them using special examinations. This is to protect, for example, sensitive and motor functions or the auditory pathway. Only in the case of surgery with local anesthesia is it possible to monitor the speech center. Sometimes it is necessary to interrupt the operation to check the success of the operation by means of imaging (CT, MRI).
After the operation, the doctor stops bleeding and closes the wound, of which usually only a scar remains later on. Until the patient’s condition is stable, he or she remains in a monitoring ward. The doctor usually orders another CT or MRI later in the procedure to check the results of the surgery. In addition, patients usually receive a cortisone preparation for a few days after the operation. It is to prevent the brain from swelling badly.
Some brain tumors can only be treated with radiation therapy. In others, this is only one of several treatment measures.
Radiation is used to destroy the brain tumor cells while sparing neighboring healthy cells as much as possible. In general, it is not possible to exclusively detect the brain tumor. Thanks to good technical possibilities, however, the area to be irradiated can be calculated very well with prior imaging. The irradiation is done in several single sessions, because this improves the result.
In order not to have to determine the tumor area anew at each session, individual face masks are made. This allows the head of the affected person to be placed in exactly the same position for irradiation each time.
Side effects sometimes occur during radiation therapy. For example, sometimes the skin over the irradiated area becomes red. Headaches and nausea also occur. The doctor will inform you about possible side effects before radiation therapy and tell you how to deal with them.