Brain tumor implies growth and mass of abnormal cells that form in the course of cloning during regeneration of brain cells. Causing pressure inside the skull, brain tumors can be seen at all age groups from neonatal period to advanced ages. This compression and pressure hinders the brain to fulfill its functions implicitly and patients show various symptoms. Especially severe and long-lasting headache, which is seen in approximately 60% of the patients, is one of the critical signs.
Early diagnosis is of great importance in brain tumors which are generally classified as benign and malign. Since not all brain tumors are life-threatening, accurate intervention and early diagnosis have critical roles in treatment of tumors. Tumors can be taken under control thanks to early diagnosis and novel treatment methods tailored in conjunction with developments in medicine.
How does it occur?
Similar to tumors developing in different body parts, brain tumors originate from cell anomalies. Cells develop exactly like living organisms and grown and dead cells are replaced by the new ones. If cells turn into a different structure, grow excessively or if the new cells do not die during this renewal process, those cells start forming masses. The exact cause of these masses, called tumor, are unknown. However, the significant role of genetic factors and exposure to radiation in tumor formation is acknowledged.
Although factors causing brain tumor are still investigated today, some factors are known to be effective in formation of tumor. These factors are:
- Exposure to radiation and various carcinogenic chemicals,
- Various viruses particularly HIV infection,
- Use of mobile phones (This is one of the suspected causes, although has not been proven yet.)
What are the symptoms?
Symptoms of brain tumor show inter-patient variations depending on certain factors. Symptoms vary based on the location, size, growth rate and type of tumor. Symptoms develop based on specific reasons such as compression of tumor on nerve ends and fluid accumulation in brain due to giant tumors.
Since brain manages all body movements, the symptoms can be seen in different regions. Although brain tumor is characterized with severe headache, general symptoms are as follows:
- Severe headache,
- Fainting attacks similar to epilepsy seizures,
- Nausea and vomiting,
- Balance and gait disorders,
- Numbness and loss of sensation in arms and legs,
- Vision disorders like blurred vision and diplopia,
- Speech disorders,
- Altered mental status,
- Personality changes,
- Slowed movements and facial expression.
What Are the Types of Brain Tumors?
Brain tumors are classified upon their locations and configurations. World Health Organization (WHO) classified the brain tumors under 7 main categories in 2016. There are more than 30 tumor types with different characteristics under these main categories. The relation of all tumors inside the brain with nervous system is one of the most important factors in this differentiation; some tumors can originate from other abnormal cells, vessels, meninges or other tumors in a different part of body.
Basically, there are two types of brain tumors: primary and secondary tumors. Tumors develop in any part of brain, in brain tissue and spread from there are called primary tumors. Glioma and meningioma originating from glial cells are one of the most common types of primary tumors which can be benign or malignant.
Cancer cells located in organs such as stomach, lung, and intestines can reach to brain via blood vessels. New cancerous cells forming in body as a result of these cells are called secondary tumors. These cells can also be called metastases.
Benign tumors are caused by reasons that do not originate from brain cells and they do not contain cancer cells. Benign tumors that generally grow slowly have clear demarcations; therefore, they can be entirely or partially remove over the brain tissue with surgical intervention. Benign tumors that usually do not spread to the neighboring tissues compress the nearby tissues and hinder some brain functions when they reach a large size. Moreover, benign tumors can turn into malignant tumors, although very rarely. These tumors have a low risk of recurrence and metastasis.
Benign tumors include dermoid and epidermoid tumors, colloidal cyst, pituitary adenomas, neurinomas, hemangioblastoma and astrocytoma while the most frequently seen benign tumors are meningiomas.
Growing and spreading rapidly, malignant tumors are the primary reason of cancer. Malignant tumors with unclear demarcations damage the neighboring brain tissue and hinder the brain to fulfill its functions. It is not preferred to entirely remove these tumors formed by cells which are responsible for fulfill the brain functions with surgical approach. Entire removal of these cells leads to losses of brain activities. Malignant tumors can re-grow after surgery.
Glial tumors and metastatic brain cells are frequently seen malignant tumors. Glial tumors, which are one of the most frequently seen brain tumors and cause cancer, grow in an uncontrolled manner. Cancerous cells also affect the intact cells around them as a result of this rapid growth. Various treatment methods are utilized in this process divided as grade I, grade II, grade III and grade IV.
Metastatic cells, on the other hand, develop when cancerous cells in a different body part outside of brain spread to the brain. Comprising of approximately 10% of the all brain tumors, metastases can originate from different organs such as lungs, stomach and pancreas, while the origins of those cancerous cells cannot be determined for some patients.
How is it diagnosed?
Brain tumor is diagnosed in the light of imaging methods, patient’s medical history and neurologic examination. Especially Magnetic Resonance (MRI) and brain tomography are primarily utilized for diagnosis. MRI provides information about anatomic condition as well as biochemical structure of brain. Besides, imaging methods can also help determining size, configuration and location of tumor. In some cases, angiography, cranial x-ray, CT and biopsy can also be used. Brain tumor can be definitely diagnosed in the light of pathological examinations.
What Are the Treatment Methods?
In addition to surgical procedures, radiation and chemotherapy are also used for treatment of brain tumors. Accurate treatment method is selected considering the size, location and type of tumor, as well as health status of patient.
Today, there are quite successful surgeries are carried out to entirely or partially remove the tumors. Surgeries consist of microsurgeries performed under guidance of biopsy and microscopic evaluation. Biopsy is carried out with a needle punctured near the tumor to learn the type of the tumor. Microsurgery is generally performed to remove the entire tumor. Microsurgery method is preferred to decrease the intracranial pressure and to eliminate the symptoms caused by the tumor.
Generally preferred to treat malignant tumors, radiotherapy implies applying x-rays or gamma rays to the tumor region at certain intervals. The aim of radiotherapy, which is performed without harming the intact tissues around tumors, is to prevent growth of cells or completely destruct those cells.
It is targeted to prevent the cell growth with the drugs administered at certain intervals within the scope of chemotherapy. Commonly administered to cancerous, malignant tumors, chemotherapy generally prolongs patients’ lifetime.
Frequently Asked Questions
Who are under higher risk for brain tumor?
Brain tumors can be seen at any age starting from birth. However, they are more frequently seen in individuals older than 70 years of age and children younger than 10 years of age. In addition to age, sex and being Caucasian are also included in risk factors. Brain tumors are more commonly seen in men comparing to women. Risk of brain tumor is higher in individuals whose familial history is significant for brain tumor.
Is every headache a sign of a brain tumor?
No. Headache has numerous reasons such as migraine, heavy stress or hypertension. Headache shown as a sign of brain tumor is very severe, sudden-onset and unmanageable. This severe pain may also be a sign of cerebral hemorrhage. In some cases, pain is mild but lasts for a very long time. In these cases, patients should necessarily consult a specialist.
Should brain tumors be entirely removed?
No. Follow-up without surgery may be sufficient for some benign or congenital tumors. It is sufficient to follow-up these tumors at certain intervals. For malignant tumors, on the other hand, suitable treatment method should be used.
What is the incidence of brain tumor?
Today, incidence of brain tumor is 5/100.000; however, specialists predict an increase in number of patients in the future years. One of the important reasons of this is rapid increase in number of individuals at advanced ages and development in imaging techniques.