What is Brain Tumor?

A brain cancer is an abnormal growth that originates in the brain or a metastatic tumor that has migrated from tumor cells that have originated in other distant parts of the body. It may occur in any tissue contained in the skull, including the brain, the cranial nerves, the meninges, pituitary gland, and the pineal gland.

Doctors diagnose brain tumor by conducting the neurological exam and tests like MRI, CT scan, and biopsy.

Treatment options need to be explored after watchful waiting and they include surgery. Radiotherapy, chemotherapy and targeted therapy. A combination of the different types of treatment procedures is usually prescribed. Read more on Treatment for Brain Cancer here

Patients most commonly present with signs of intracranial pressure (e.g., headache, mood swings, nausea, vomiting and gait abnormality. Read more on Symptoms of Brain Cancer here

According to the National Brain Tumor Society, there are over 120 different types of brain tumors. The most common of which are gliomas that originate in the glial (supportive) tissue. About a third of all primary brain tumors and other nervous system tumors form from glial cells.

There are over 120 different types of brain tumors. The World Health Organization (WHO) developed a classification and grading system to standardize communication across heath networks across the globe. The aim is to plan treatment and predict outcomes more accurately and in an organized fashion.

But based on site of origin, brain tumors are classified into two types:

a. Primary brain tumors originate in brain tissue and tend to stay there.
b. Secondary brain tumors are more common. These cancers start somewhere else in the body and travel to the brain. Lung, breast, kidney, colon, prostate and skin cancers are among the commonest primary cancers that can metastasize to the brain.

Some brain tumors contain cancer cells and others don’t:

• Benign brain tumors are free from cancer cells. They grow slowly, can definitely be removed, They seldom spread to the surrounding brain tissue. Depending on the location of the tumor, they can be life-threatening.
• Malignant brain tumors contain cancer cells. The growth rates differ, but cells can invade healthy brain tissue surrounding it. These seldom spread beyond the brain or spinal cord.

Different Types of Brain Tumors

In adults, the most common types of brain cancer are:

• Astrocytomas. These usually start in the part of the brain that occupies most space the cerebrum. They cause seizures or shifts in behavior.
• Meningiomas. These are the commonest primary brain tumors in adults. They are most likely to occur in 70s or 80s . They start in the meninges, the lining of the brain. They can be of grades 1, 2, or 3. They are benign and metastasis is rare.
• Oligodendrogliomas. These arise in the cells that make the covering that protects nerves. They are usually of grades 1, 2, or 3. They usually grow slowly and don’t spread to nearby tissue.

Among children, the most common tumor types are:

• Medulloblastoma: The tumor usually arises in the cerebellum. It’s sometimes called a primitive neuroectodermal tumor. It is grade IV.
• Grade I or II astrocytoma: In children, this low-grade tumor occurs anywhere in the brain. The most common astrocytoma among children is juvenile pilocytic astrocytoma. It’s grade I.
• Ependymoma: The tumor arises from cells that line the ventricles or the central canal of the spinal cord. It’s most commonly found in children and young adults. It can be grade I, II, or III.
• Brainstem glioma: The tumor occurs in the lowest part of the brain. It can be a low-grade or high-grade tumor. The most common type is diffuse intrinsic pontine glioma.

The common ones of brain tumor are:

1. Gliomas

• Astrocytoma
• Pilocytic Astrocytoma (grade I)
• Diffuse Astrocytoma (grade II)
• Anaplastic Astrocytoma (grade III)
• Glioblastoma Multiforme (grade IV)
• Oligodendroglioma (grade II)
• Anaplastic Oligodendroglioma (grade III)
• Ependymoma (grade II)
• Anaplastic Ependymoma (grade III)

2. Craniopharyngioma

3. Epidermoid

4. Lymphoma

5. Meningioma

6. Schwannoma (neuroma)

7. Pituitary adenoma

8. Pinealoma (pineocytoma, pineoblastoma)

People with a brain tumor may experience either general or specific symptoms.

The symptoms of a Brain Tumor are:

• Seizures or paralysis.
• Headaches.
• Personality and memory changes.
• Memory loss and confusion.
• Nausea and vomiting.
• Fatigue.
• Difficulty in swallowing.
• Changes in vision and other sensory perceptions.

Other symptoms of Brain Tumor:

• Sleep issues and drowsiness.
• Changes in ability to walk and conducting daily affairs
• Balance Issue
• Facial numbness
• Depression
• Trouble with coordinated movement of limbs.

A risk factor is that which increases the chance of getting a disease. Most brain tumors are not linked with any known cause. Research studies show the a few risk factors that may raise the risk of developing brain tumors

1. Ionization Radiation

It is a high dose of -rays that can cause cell damage, leading to brain tumor. People exposed to ionization radiation may have increases risk of brain tumors like meningioma or glioma. Read more on types of brain tumors here.

Yet, radiation induced tumors are still very rare.

2. Other Exposure

Exposure to industrial chemicals or solvents is associated with increase in the risk of developing brain tumor. Although there is no conclusive evidence, there is higher risk for individuals who work in oil refining rubber manufacturing and drug manufacturing industries.

3. Family History:

The incidence rate for this is low, and only a small number of families have several members with brain tumors. Von Hippel-Lindau disease, Li-Fraumeni syndrome, and Neurofibromatosis (NF1 and NF2) are inherited conditions found in histories of patient families.

• Neurofibromatosis type 1 (NF1)

Also known as von Recklinghausen disease, this is the most commonly linked to brain and spinal tumors. People affected gave higher risks of schwannomas, meningiomas, certain types of gliomas and neurofibromas (which are benign tumors of peripheral nerves). Changes in the NF gene cause this disorder. Half the number of cases reported to have been inherited.

• Neurofibromatosis type 2 (NF2)

Less common than NF1, this condition is linked to vestibular schwannomas (acoustic neuromas), which almost always occur on both sides of the head. It is associated with a raised risk of meningiomas or spinal cord ependymomas. Alterations in the NF2 gene are usually responsible for neurofibromatosis type 2. Half the number of cases reported to have been inherited.

• Tuberous sclerosis

This condition is caused by TSC1 or TSC2 genes. People affected may have subependymal giant cell astrocytomas (SEGAs), which are low grade astrocytomas that develop beneath the ependymal cells of the ventricles. They may also have other benign tumors of the brain, skin, heart, kidneys, etc.

• Von Hippel-Lindau disease

Patients affected with this condition tend to develop benign or cancerous tumors in different body parts including hemangioblastomas (benign blood vessel tumors in the brain, spinal cord, retina, inner ear, kidney, adrenal gland and pancreas. Mutations in the VHL gene cause this condition, and it is mostly inherited.

• Li-Fraumeni syndrome

Patients affected are at a higher risk of developing gliomas along with breast cancer, soft-tissue sarcomas, leukemia, adrenal gland cancer and other types. Mutations in the TP53 gene cause this condition.

• Other syndromes

Other inherited syndromes linked with brain and spinal tumors are:

– Gorlin syndrome (basal cell nervous syndrome)
– Turcot syndrome
– Cowden syndrome

4. Gender

While there is no rule of thumb for brain tumor in males or females it has been noted that meningiomas are twice as likely to develop in women and medulloblastomas are more frequently reported in men.

5. Age

In general the frequency of brain tumor occurrences in older people is high. The age factor differs according to type and location of cell. For example, adults have a very low risk of developing medulloblastomas, gliomas are most common in adults. The occurrence of meningiomas and craniopharyngiomas are more frequent in adults over the age 50. It is still reported that these tumors may occur at any age.

6. Immunity

Low immunity in people can increase the risk of developing lymphomas in the brain. A weakened immune system may be caused by treatments for other cancers, treatment to prevent rejection of transplanted organs, diSeases like acquired immunodeficiency syndrome (AIDS). Some cases may also be congenital (present at birth).

Tumors are graded in accordance with how normal or abnormal the cells appear. Doctors plan treatment based on this observation. Staging also gives them an idea about how fast brain tumor is likely to spread. The following are brain tumor stages.

Grade 1 brain tumors are low grade malignant and slow-growing. It is easy to confuse them with identical healthy cells.

Grade 2 brain tumors are malignant and slow-grading. They have high chance of recurrence and are likely to spread to surrounding tissues.

Grade 3 brain tumors appear abnormal and actively metastasize into surrounding regions of the brain and are very likely to recur.

Grade 4 brain tumors look highly malignant and actively metastasize into surrounding tissues of the brain. Rarely some benign tumors can become malignant and a lower grade tumor may recur with a higher grade.

When the patient presents with suggestive symptoms of brain tumor, the physician will do a thorough medical history and physical examination. Then a plan for screening tests and procedure is drawn out for diagnosis of brain tumor

Your doctor may decide to do some of the following tests:

• Physical exam
• Mental assessment
• Eye exam or eye test
• Hearing tests
• Testing your facial muscles
• Testing your swallowing or gag reflex
• Checking the strength in your limbs
• Checking your balance or coordination
• Checking the sensation on your skin

Imaging for Brain Tumor can be done by the following ways:

1. Computed tomography (CT) scan.

A CT scan creates a three-dimensional picture of inside the body using X-rays that are taken from different angles. A special kind of dye is also used to make the image clearer. The dye can be injected into the patient’s veins or can be given as a liquid to swallow. However, even in a CT scan, tumors that are very small are difficult to recognize.

CT angiography (CTA):

Here, the patient is injected with a contrast dye through an IV line while the scanner is at work. This creates detailed images of the blood vessels in the brain helping doctors to plan surgery.

2. Magnetic Resonance Imaging (MRI).

The MRI scan unlike the X-ray uses magnetic waves to give a detailed image of the internal parts of the patient’s body. The MRI is also known to detect the tumor size and a dye called a contrast medium is injected into the patient’s veins to give a more detailed view.

Special types of MRI are as follows:

a. Magnetic resonance angiography (MRA) and venography (MRV)

Used to get images of the blood vessels, this is done during or before surgery.

b. Magnetic resonance spectroscopy

Done as a part of MRI, MRS measures biochemical changes in any area of the brain.

c. Magnetic resonance perfusion

A special type of MR image is taken to determine the amount of blood going to different parts of the brain after a contrast dye injection. This indicates the site of the tumor as a faster growing tumor may need more blood. This in return helps determine which tissues need biopsy to be done.

d. Functional MRI (fMRI)

This test determines the functions different regions of the brain handle so that doctors avoid these regions while planning treatment modalities.

3. Biopsy

A biopsy is a procedure where a sample tissue is removed and looked at under a microscope to see if it is cancerous. Biopsies can be done through different methods like needle biopsy, laparoscopic biopsy and surgical biopsy. For brain tumors, the biopsies are of two types:

a. Stereotactic biopsy

This type of biopsy is done based on imaging tests.

b. Surgical or open biopsy (craniotomy)

If imaging tests confirm that the tumor exists, the neurosurgeon may not do a needle biopsy. Instead he may remove tumorous regions through a surgery called craniotomy. Removing most of the tumor is called debulking.

4. Positron emission tomography (PET) scan

The patient is injected with a mildly radioactive substance (usually a sugar called FDG) and this collects mainly in tumor cells. A camera that is of less quality than CT and MRI scans helps build information for further action.

5. Positron emission tomography (PET) scan

A chest X-ray looks for tumors in the lung if a tumor is found in the brain. This is because many instances of metastasis into the brain have been reported of lung cancers.

6. Electroencephalography

An EEG is used for a measurement of electrical activity of the brain. It also makes it possible to monitor seizures.

7. Evoked potentials.

Like EEG’s, involve electrodes that measure electrical activity; only those of the nerves. They often detect acoustic schwannoma, a noncancerous tumor.

8. Lumbar puncture or spinal tap.

In this procedure, the doctor uses a needle to take sample of cerebrospinal fluid (CSF) to look for tumor cells, blood, or tumor markers.

9. Myelogram

This is used to find if the tumor has spread to the spinal fluid and other parts of the brain.

Brain Tumor Treatment Follow-up

Treatment For Recurrent Brain Tumor

Implants Used in Brain Tumor Treatment