Brain Tumors

To simply define, a brain tumor is a growth of abnormal cells in the brain.

Brain Tumors come in various forms and categories and they may be noncancerous (benign) OR cancerous (malignant).

A Primary Brain Tumor is one that begins in your brain first. A Secondary Brain Tumor is one that begins in other parts of the body and is cancerous and then spreads to the brain. The secondary brain tumors are mostly the metastatic ones.

How fast a brain tumor grows can vary largely. The location and the rate at which it grows will determine how much impact it will make on the functioning of the nervous system.

Brain Tumor treatments vary based on their type, size, and location.

Here’s a link to the World Health Organization’s Reclassification of Tumors of Central Nervous System

There are various types of Brain Tumors:

Symptoms

The symptoms or signs of a brain tumor largely vary and mainly depend on the size, location, and growth.

Usually, symptoms caused by brain tumors may include:

  • The onset of frequent Headaches or change in the pattern of headache
  • Unexplained vomiting
  • Difficulty with balance
  • Blurred vision or partial or full loss of vision, OR loss of peripheral vision
  • Seizures, especially in someone who doesn’t have a history of seizures
  • Loss of sensation or movement in limbs (hand/legs)
  • Difficulty in speaking OR speech
  • Increased frequency of getting very tired
  • Increased confusion in daily routine matters
  • Difficulty in executing simple commands
  • Changes in personality or behavior
  • Partial or Complete Loss of hearing
  • and many more

Causes

As stated above Brain Tumors can be Primary or Secondary. In the case of primary brain tumor, it originates in the brain itself OR in tissues close to it, such as meninges, cranial nerves, pituitary gland, or pineal gland.

Primary Brain Tumor triggers when normal cells develop mutations (changes) in their DNA. A cell’s DNA contains the instructions that tell a cell what to do. Whereas, in the case of mutation, DNA tells the cells to grow and divide rapidly and to continue living when the healthy cells would die. As a result, a mass of abnormal cells called Tumors starts occupying the space in the cranial area of the brain putting pressure on the parts of the brain.

There are many different types of primary brain tumors that exist. Their name suggests from which cells they have originated. Examples:

  • Gliomas. These tumors arise from the abnormal glial cells in the brain or spinal cord and include astrocytomas, ependymomas, glioblastomas, oligoastrocytomas, and oligodendrogliomas.
  • Meningiomas. These tumors arise from the membranes that surround the brain and spinal cord, called meninges. These are mostly benign (non-cancerous).
  • Schwannomas (Acoustic Neuromas). These tumors arise from the nerves that control the balance and hearing function leading from your ears to your brain. These are mostly benign (non-cancerous)
  • Medulloblastomas. These tumors arise from the lower back part of the brain and have a tendency to spread through the spinal fluid. These tumors are most common in children, however, they can occur at any age. These are malignant tumors (cancerous).
  • Germ cell Tumors. These tumors arise during childhood when the testicles and ovaries will develop. However, sometimes, they affect other parts of the body including the brain.
  • Craniopharyngiomas. These tumors arise near the brain’s pituitary gland, which secretes hormones that control many body functions. These tumors grow very slowly but they can affect the pituitary gland and other structures near the brain.

Usually, primary brain tumors are less common in adults than secondary brain tumors in which cancer begins elsewhere in the body and spreads or reaches the brain.

Secondary brain tumors result from the cancer that has originated elsewhere in the body and then spreads to your brain. Spread of cancer from the point of origin to other parts of the body is called Metastasis. Secondary brain tumors are metastatic in nature.

Secondary brain tumors mostly occur in people having history of cancer. Rarely, a metastatic brain tumor can be the first sigh of cancer that began elsewhere in body. These are the most common in adults.

Usually any cancer can spread to the brain, but most common forms of cancer include:

  • Breast Cancer
  • Colon Cancer
  • Kidney Cancer
  • Lung Cancer
  • Melanoma

Risks

The cause of tumor isn’t clear in most primary brain tumors. However, in recent researches doctors have identified some factors that have potential to increase risk of a brain tumor.

These risks include but not limited to:

  • Radiation Exposure. Anyone who have been exposed to ionizing radiation at the highest risk of brain tumor. Examples of ionizing radiation may include Radiation Therapy used to treat cancer, OR radiation exposure caused by atomic bombs or reactors.
  • Family history of brain tumors. Although in small percentages, but brain tumors occur to people having a family history of brain tumors OR a family of hitory of genetic syndromes.

Diagnosis

Doctors may recommend a number of tests and/or procedures in suspected brain tumor patients. These include:

  • Imaging Tests. Magnetic Resonance Imaging (MRI) is the most common imaging test used to diagnose brain tumors. In some cases a contrast MRI is done by injecting a dye through vein in patient’s arm for more detailed study. There are number of specialized scan components such as functional MRI, Perfusion MRI and Magnetic Resonance Spectroscopy which may help the treating doctor to evaluate the tumor and setup a plan for treatment. In certain situations doctors recommend a Computerized Tomography (CT) and Positron Emission Tomography (PET).
  • Histo/Cytopathology (Biopsy). A biopsy can be conducted pre-operative, intra-operative or post operative. During biopsy a sufficient amount of tissue of tumor is extracted via a fine needle in case of pre-operative condition OR can be extracted as a part of an operation to remove the brain tumor. In very difficult, or sensative areas / parts of brain, a stereotactic needle biopsy may be done for brain tumors. Neurosurgeon drills a small hole into the skull, and then a fine thin needle is inserted throught the hole. Tissue is then removed using that needle guided by either a CT or an MRI scanning. Biopsy sample is then reviewed microscopically to find out if its malignant (cancerous) or benign (non-cancerous). In some high tech laboratories, some tests may even give clues to doctors about the prognosis and treatment options. Biopsy study provide exact information about the which type of brain tumor it is and it is a very complex process. Its always recommended to get second opinion at an established medical center where many brain biopsies are evaluated every year.