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Brain tumor surgery Grade 3 Astrocytoma 31-year-old woman - 6th year postoperatively. She relapsed and became GBM. I operated 3 more times. He lived 5 years after being diagnosed with GBM.. 

Beyin Tümörlerinin belirtileri nelerdir?

Beyin tümörlerinde baş ağrısı, bayılma, mide bulantısı - kusma, ilerleyici nörolojik defisit ve başka birçok belirtiler olur. Bunlarla ilgili olarak aşağıdaki videoyu izleyebilirsiniz.



A brain tumor may arise from brain cells or other cells that support the brain. Classically, we can examine it in two groups: benign and malignant brain tumors.  In order to distinguish between good and bad, it is necessary to operate and examine. It is possible to predict the behavior of the tumor before surgery.  

Classifications of brain tumors and treatment guidelines according to these classifications


Below I have provided some brief information about brain tumors that may be a guide:

If someone close to you has a headache, fainting, vomiting, losing consciousness, etc.

or if a brain tumor was revealed accidentally in an MRI or tomography

First of all, the following questions must be answered.

1-      Is the tumor actually a mass that originates from another part of the body but has spread to the brain?

2-      Does the tumor originate from the brain itself?

3-      Is the tumor a mass that originates from the membranes of the brain and puts pressure on the brain from the outside?

4-      Is the tumor on the surface of the brain or is it deeply located?

5-      Is the tumor in a sensitive area of the brain where surgery could cause serious damage to the brain?

Brain tumors are classified according to the answers to these questions and their pathological examinations.

Classification helps us understand how tumors behave and how long patients survive.

It is very important for prediction.

What are the types of brain tumors?

Generally, brain tumors in the central nervous system are examined in 9 separate categories.

1- Tumors of brain tissue (Neuroepithelial brain tumors).

2- Nerve-derived tumors (nerve roots originating from the brain and spinal cord)

3- Tumors of the membranes of the brain (meningeal tumors)

4- Tumors related to blood diseases (Hematopoietic tumors)

5- Tumors arising from prenatal cells (Germ cell)

6- Cyst and tumor-like formations

7- Pituitary region tumors (sellar region tumors)

8- Tumors extending from outside to the brain region

9- Tumors that spread from another part of the body (Metastasis)

There are many classifications of brain tumors. Until 2016, the most well-known was the 2007 WHO classification. In 2016, a working group was formed by taking the opinions of 117 participants from 20 countries. The working group included 35 neuropathologists and neuro-oncology clinicians and scientists from 10 countries  To unite his opinion  He held a consensus meeting that lasted 3 days.  Following the consensus meeting, the 2016 WHO classification was published.

In the 2016 WHO classification, genetic and molecular features, as well as histological features, were also evaluated in diagnosis. However, basic histological criteria are still used to determine the grade of brain tumors.

What causes brain tumor?

The brain contains nerve cells and cells that support nerves. If we could somehow remove the nerve cells from the brain, all the remaining cells are generally called astrocytes or glial cells. Astrocytes are called astrocytes, which can be translated into Turkish as star-like cells, because they appear to have radial arms like stars under the microscope. The majority of brain tumors arise from various astrocyte cells.

Glial cells are examined in 4 parts.

1- Astrocytes

2- Oligodendroglia

3- Microglia

4- Ependymal cells

Uncontrolled proliferation of each cell or group of similar cells means tumor formation. For this reason, pathologists and scientists examine tumors under a microscope, stain them with various dyes, perform immunohistochemical tests, and finally, when they deem necessary, they also perform genetic tests and give the tumors a name.

It can be thought that in order for a brain tumor to occur, the genetic structure of the cells that cause the tumor must be disrupted. Nowadays, genetic examinations are also performed to diagnose tumors. However, this does not mean that the disease is transmitted familially. The damaged structure is only in that person. Familial transmission has not been demonstrated in most brain tumors.

There are also some brain tumors that are known to be inherited in families. these

1-Hemangioblastoma is seen in Von-Hippel Lindau syndrome.

2-Subependymal giant cell astrocytoma may be seen in tuberous sclerosis disease.

3-Optic glioma, astrocytoma and neurofibroma can be seen in Neurofibromatosis Type 1.

4- Acoustic neuroma, meningioma, ependymoma and astrocytoma can be seen in Neurofibromatosis Type 2.

Astrocytoma and primitive neuroectodermal tumor can be seen in 5-Li-Fraumeni syndrome.

6-Advanced stage tumors such as glioblastoma and medulloblastoma may be seen in Turcot syndrome.


Staging in brain tumor:

There is also a type of grading system we call grade or stage in the examination of brain tumors. Brain tumors are classified into 4 grades (4 stages if we try to translate them into Turkish, although they do not have the same meaning). In other words, the name of the tumor is different, and presumably the grade it is included in is different. We call Grade 1 the best-behaved tumor and Grade 4 the worst-behaved tumor. The name, grade, behavior, and division rate of each tumor are data for us to estimate how long the patient will survive. However, another issue that is as important as these is the general condition of the patient, that is, whether he can do his own work or not and whether he is self-sufficient. People who are in good general condition and are self-sufficient and can do their own work live longer. In addition, brain tumors with the same characteristics arising in sensitive areas of the brain may have different results than those occurring in adjacent or distant parts of the brain. In general, tumors that arise on the left side of the brain and tumors that arise on the right side have different results. Because there is mostly a speaking and understanding area on the left side, the tumor may not be completely removed. This may cause the tumor to grow back much faster and cause the patient to die.


How do we estimate the growth rate of brain tumors?

The faster a tumor grows, the more cells it has and the more cells of different sizes and shapes it has. The faster it grows, the more unhealthy the vascular structure becomes. Fast-growing tumors undergo necrosis because the interior cannot receive nourishment due to unhealthy developing vessels. Therefore, by looking at the patient's brain MRI before surgery, we understand that if the tumor has necrosis, it is a fast-growing malignant tumor.

We also look at the Ki67 index. For this, the patient is first operated on. The tumor is either completely removed or a piece is removed. The taken pieces are sent for pathological examination.


In particular, immunohistochemical examinations are requested. Many pathology laboratories do not perform these examinations on the grounds that they are advanced examinations.


Ki67 index, one of the immunohistochemical examinations, shows us how many tumor cells are dividing. Ki-67 is an immunohistochemical staining method used to identify cells that exit the G0/G1 phase and enter the S phase during the proliferation process.  If it is below 5% in age 67, we think that the tumor divides and proliferates more slowly and we consider its grade to be lower. The behavior of these tumors is likely to be better than the larger ones at Ki 67. We consider those with levels greater than 7-9% of 67 as having anaplastic behavior. There are also very malignant tumors with a Ki67 ratio of 15% or 40%.

The unluckiest patients who undergo brain tumor surgeries are those diagnosed with glioblastoma. Patients diagnosed with glioblastoma usually survive for 1-2 years. Those who live longer are very rare. The most important condition for these patients to live longer than 1 year is the removal of the tumor to be operated on. The second is radiotherapy and chemotherapy after surgery. The third is to undergo surgery again when the tumor recurs. Glioblastomas definitely recur, and when they recur, they need to be operated on again, if possible. 


In the tables below, I have written the names of the tumors arising from the glial cells and nerve cells of the brain in the 2016 classification and the stages, that is, their grades, against some of them.

Diffüz Astrositik ve oligodendroglial tümörler

Diffüz Astrositoma, IDAH-mutant
Grade II
Diffüz Astrositoma, IDAH-wildtype
Grade II
Diffüz Astrositoma, NOS
Grade II
Anaplastik Astrositoma, IDAH-mutant
Grade III
Anaplastik Astrositoma, IDAH-wildtype
Grade III
Anaplastik Astrositoma, NOS
Grade III
Glioblastoma, IDAH-mutant
Grade IV
Glioblastoma, IDAH-wildtype
Grade IV
Glioblastoma, NOS
Grade IV
Diffüz midline glioma, H3 K27M-mutant
Grade IV
Oligodendroglioma, IDH-mutant ve 1p/19q kodelesyonu var
Grade III
Oligodendroglioma, NOS
Anaplastik Oligodendroglioma, NOS
Anaplastik Oligoastrositoma, NOS
Oligoastrositoma, NOS
Diğer Astrositik tümörler
Pilositik astrositoma
Grade I
Subependimal giant cell astrositoma
Grade I
Pleomorfik Xanthoastrositoma
Grade II
Anaplastik Pleomorfik Xanthoastrositoma
Grade III

Ependimal Tümörler

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Diğer Gliomlar

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Koroid Pleksüs tümörleri

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Nerve cell  and Glial cell mixed tumors with nerve cells

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