Brain Tumors

Introduction

 

A brain tumor is an abnormal growth of the neuron cells in the cerebral cortex. Brain tumors occur due to genetic error in the neuron cell bodies that change the cellular mechanism engaged in the transmission of sensory information. This mutation of cells enables the abnormal growth of the tumorous tissue, while the healthy brain cells suffer destruction.

 

Since the mutated neuron cells of the tumor multiply uncontrollably within the confines of the skull, they apply pressure on the surrounding tissues of the brain. Therefore, oxygen supply is cut off by the pressure of tumorous growths on the blood-supplying system and the functions of the brain become impaired which results in the death of neuron cells.

Primary and Secondary Brain Tumors

Primary Brain Tumors

Primary brain tumors occur in the brain or the surrounding structures and tissues, such as the pituitary gland, cranial nerves, the meninges, or the pineal gland. This type of brain tumor results from the mutation of the neuron cells’ DNA that suppresses the healthy cells and supports the multiplication of the tumorous neuron cells.

 

The most common primary brain tumors are the following:

  • Glioblastoma;
  • Pineal region tumors;
  • Glioma;
  • Acoustic neuroma;
  • Meningioma, etc.

Secondary (Metastatic) Brain Tumors

The tumors that initially appear in some part of the body area and later spread (metastasize) to one or several other areas of the brain are known as secondary brain tumors. This type of tumor forms from mutated cells that have separated from the primary tumorous growth and have entered the brain’s bloodstream. This is why secondary brain tumors are also labeled as metastatic tumors.

 

The most common secondary (metastatic) brain tumors are:

  • Breast cancer;
  • Lung cancer;
  • Melanoma (skin cancer);
  • Colon cancer;
  • Kidney cancer.

How Are Brain Tumors Classified?

While some brain tumors are cancerous (malignant), meaning they impose an extremely high risk of spreading onto other organs, other types of brain tumors are non-cancerous (benign).

What Are the Types of Benign Brain Tumors?

The benign (non-cancerous) brain tumors do not invade other areas or structures of the brain. They are formed and stay in their place of origin, which makes them easier to completely remove through surgery than the metastasizing malignant tumors.

 

The list of benign brain tumor types consists of:

  • Gangliocytomas;
  • Meningiomas;
  • Pineocytomas;
  • Schwannomas;
  • Pituitary adenomas;
  • Glomus jugulare paraganglioma;
  • Craniopharyngiomas;
  • Chordomas.

Gangliocytoma

Gangliocytoma refers to a rare and genetically inherited tumor that affects the central nervous system. The tumor lumps typically occur in the temporal lobe of the brain, but it’s not unusual for the gangliocytoma to form in the spinal cord, the third ventricle, or the cerebellum.

 

The typical symptoms that point to the presence of a gangliocytoma in the brain include:

  • Persistent pressure on the cortical structures;
  • Headaches.

Meningioma

When the tumorous neuron cells form on some of the meninges of the brain, they’re labeled as a meningioma. This type of brain tumor can occur on any of the three protective membranes of the brain.

 

Meningiomas are slow-growing tumors that typically do not display any severe symptoms. However, the occurring symptoms resemble the general symptoms of all brain tumors.

Pineocytoma Tumors

The tumor of the pineal gland is labeled as a pineocytoma. The abnormal multiplication of neuron cells in the case of pineocytoma can lead to hydrocephalus, problems with vision, and severe headaches accompanied by nausea and vomiting.

Schwannoma

Schwannoma is a tumorous growth that occurs in the layer comprising the nerves of the peripheral nervous system. It’s characterized by a lump that can be easily seen under the skin, as well as prickling sensations, numbness, and pain spreading in the face or any other part of the body.

 

When a schwannoma affects the nerve located between the brain and the inner ear, it is referred to as acoustic (vestibular) schwannoma. This type of schwannoma triggers symptoms such as ringing in the ears, inability to maintain balance, etc.

Pituitary Adenoma

This type of tumor is classified as a benign and non-invasive tumorous formation on the pituitary gland. Since the pituitary gland is responsible for the control and regulation of a multitude of vital processes in the body, the symptoms triggered by the pituitary adenoma mainly affect the production of hormones.

 

 

The list of pituitary adenoma symptoms includes:

  • Gigantism/Acromegaly (Abnormal growth in both children and adults due to the hyper-lactation of the growth hormone);
  • Hyperthyroidism;
  • Behavioral changes (hostility, anxiety, depression);
  • Sexual dysfunction;
  • Drainage of clear liquid from the nose;
  • Tiredness;
  • Vision and hearing problems;
  • Changes in body weight (extreme weight gain or loss);
  • Severe headaches.

Glomus Jugulare Paraganglioma

This type of tumor affects both the middle and inner structures located in the temporal lobe. The symptoms of glomus jugulare paraganglioma include:

  • Dysphagia (difficulty swallowing);
  • Hearing problems;
  • Partial face paralysis;
  • Severe pain;
  • Extreme discomfort at the location of the tumorous lump;
  • Hoarseness.

Craniopharyngioma

Craniopharyngioma is a benign tumor that usually forms near the pituitary gland. It triggers the following symptoms:

  • Excessive weight gain;
  • Blurred vision;
  • Ceased growth;
  • Headaches;
  • Inability to control bladder function.

 

The children affected by this type of brain cancer typically grow slower and smaller than other children of their age.

Chordoma

This rare type of cancerous brain tumor forms in the bones of the structures along the spine due to the genetic malformation of the neuron cells. The symptoms of chordoma consist of:

  • Inability to control bladder function;
  • Problems with vision;
  • Numbness;
  • Endocrine gland dysfunction;
  • Inability to swallow food or liquids.

What Are the Types of Malignant Brain Tumors?

  • Gliomas;
  • Astrocytomas;
  • Ependymomas;
  • Medulloblastomas;
  • Glioblastoma multiforme (GBM);
  • Oligodendrogliomas.

Glioma

This type of brain tumor typically occurs in the spinal cord and the brain due to the mutation of glial cells. Depending on the type of affected glial cells, this type of brain tumor can be sub-divided into the following types:

  • Astrocytoma tumors;
  • Ependymoma tumors;
  • Oligodendroglioma tumors.
Astrocytoma

Astrocytoma tumors occur as a result of mutation of the astrocytes. The affected individual typically experiences the following symptoms:

  • Severe headaches;
  • Blurring of the eyesight;
  • Difficulty speaking;
  • Memory problems;
  • Impairment of cognitive abilities;
  • A weakness of both arms and legs;
  • Seizures.

 

There are also several sub-types of astrocytoma tumors. The list includes:

  • Pilocytic astrocytoma;
  • Subependymal giant cell astrocytoma;
  • Diffuse astrocytoma;
  • Glioblastoma;
  • Pleomorphic xanthoastrocytoma.
Ependymoma

Ependymoma is a tumor affecting the ependymal cells of the central nervous system. It begins as a benign tumorous lump until it reaches the third grade of the tumor evaluation scale. This is when the abnormal neuron cells mutate further into malignant cancer and rapidly begin to invade other tissues by spreading via the cerebrospinal fluid of the brain.

Oligodendroglioma

The oligodendroglioma tumor forms by mutation of the genetic material of the oligodendrocytes, located in the white matter and the structures of the central nervous system. Seizures are the most typical symptom of an oligodendroglioma. This type of brain tumor also triggers memory and balance problems, as well as numbness.

Medulloblastoma

This cancerous brain tumor forms in the cerebellum and is frequently diagnosed in children. It affects motor movement by causing impairment of the brain area that controls and regulates the coordination of muscles. The affected patients experience an inability to maintain balance and have difficulty moving, which may appear as clumsiness. Genetic predisposition is the most common risk factor for a medulloblastoma.

Glioblastoma Multiforme (GBM)

Glioblastoma multiforme is a brain tumor that affects both the astrocytes and the oligodendrocytes that are responsible for the proper functioning of the cortical structures.  This is the most aggressive form of brain tumor with an extremely fast progression that leads to a fatal outcome.

 

A specific gene mutation is the main cause of glioblastoma multiforme. Not only do the tumorous neuron cells multiply fast, but they also spread relentlessly which makes surgical removal of the tumor even more difficult.

What Are the Symptoms of Glioblastoma Multiforme?

The patients who suffer from this aggressive brain tumor experience the following symptoms:

  • Blurred vision;
  • Seeing double images;
  • Nausea and frequent vomiting;
  • Inability to speak;
  • Impairment of cognitive functions (difficulty thinking or learning new information);
  • Loss of memory;
  • Loss of appetite;
  • Rapid loss of weight;
  • Severe headaches.

 

Radiation and chemotherapy are the main treatments for patients with glioblastoma multiforme. Surgery is an option for the removal of the tumorous cells that do not react to the aforementioned methods of tumor treatment.

What Are the Warning Signs of a Brain Tumor?

The symptoms that lead to diagnosing a brain tumor can be general or specific. The general symptoms occur due to the pressure applied to the cortical structures in the brain by the tumorous growth. On the other hand, the specific symptoms are related to the dysfunction of a specific part of the brain as a result of the brain tumor.

 

The warning signs pointing to a brain tumor encompass a wide range of symptoms that may influence the behavior of the affected individual, be location-specific, or induce debilitating medical conditions, such as:

 

  • Severe headaches with changing patterns, typically strongest after waking up;
  • Involuntary twitching or cramping of the muscles, also known as convulsions;
  • Seizures;
  • A strong pressure felt near the tumorous growth in the brain;
  • Loss of consciousness;
  • Inability to control the bladder;
  • Skin color changes (paleness, shades of blue, or gray);
  • Breathing difficulties;
  • Confusion;
  • Overall weakness and fatigue;
  • Drowsiness;
  • Being sick;
  • Problems with speech and movement;
  • Personality changes (depression, anxiety, irritability);
  • Inability to maintain balance.

Location-specific Symptoms

  • Loss of memory and inability to concentrate or speak, aggressiveness and irritability, may result from a tumorous growth in the cerebrum, the occipital lobe, or the temporal lobe;
  • If the frontal or parietal lobes are affected by a tumor, the patient may be unable to tell the left from the right side of the body, to differentiate degrees of touch, or may feel partial paralysis;
  • The pineal gland tumor can disable eye movement, so much so that looking upright may present a real challenge for the affected individual;
  • A brain tumor located in the brain stem, temporal, or occipital lobe may induce problems with vision and even lead to complete vision loss.
  • The frontal lobe tumor is also responsible for body paralysis and muscle weakness ;
  • When a tumorous growth appears in the cerebellum, the loss of balance is inevitable.

What Are the Risk Factors for Any Brain Tumor?

Exposure to radiation and some extremely toxic chemicals, such as vinyl chloride or formaldehyde, are some of the main risk factors that can cause a brain tumor. In addition, advanced age, or a family member having been affected by any type of tumor or cancer, are factors that contribute to the occurrence of a brain tumor.

Fun Facts

Did you know?

  1. Metastasis refers to the spreading of the tumorous neuron cells to the other parts of the body via the circulation of blood or the lymph system.
  2. Angioma is a formation (lump) comprised of genetically mutated neuron cells.
  3. The increasing number of brain tumors have been associated with the increased use of cell phones.
  4. Medulloblastoma is the malignant type of brain tumor that is most frequently diagnosed in children.
  5. Glioblastoma is considered to be one of the most aggressive brain tumors with a large percentage of fatal outcomes, especially in adults.
  6. We are genetically predisposed to develop tumors. Thus, if there’s a family member who has suffered from any type of tumor or cancer, the chances for a genetic mutation and abnormal multiplication of neuron cells in other family members are much higher.
  7. , For patients suffering from a wide range of medical conditions, such as Gorlin syndrome, Turcot syndrome, or Li-Fraumeni cancer syndrome, exposure to radiotherapy increases the possibility of a brain tumor.
  8. Schwannomas are also labeled as neuromas, neurilemomas, or neurolemomas.
  9. Microadenomas are tumorous formations smaller than one centimeter in size, while macroadenomas are tumors larger than 1 cm.
  10. The majority of the tumors that have been discovered so far are benign in nature.