Brain Tumor
A brain tumor, known as an intracranial tumor, is an abnormal mass of tissue in which cells grow and multiply uncontrollably, seemingly unchecked by the mechanisms that control normal cells.
The two main groups of brain tumors are termed primary and metastatic. Primary brain tumors arise from the brain or spinal cord while metastatic brain tumors, also termed secondary brain tumors, arise from other tissue and have spread to the brain.
Primary tumors are categorized further as benign or malignant.
Brain tumors can affect people of any age, including children, although they tend to be more common in older adults. The annual global age-standardized incidence of primary malignant brain tumors is ~3.7 per 100,000 for males and 2.6 per 100,000 for females. Rates appear to be higher in more developed countries (males, 5.8 and females, 4.1 per 100,000) than in less developed countries (males 3.0 and females 2.1 per 100,000).
Whether primary or metastatic, all brain tumors are serious. A growing tumor eventually will compress and damage other structures in the brain.
What are the early warning symptoms and signs of a brain tumor?
Brain tumor symptoms vary based on the location of the tumor within the brain and the size of the tumor. The severity of symptoms does not indicate how large a tumor is - small tumors can cause severe symptoms.
The most common early warning symptoms and signs of brain tumors include:
- A new onset or change in the pattern of headaches
- Headaches in the morning
- Headaches that gradually become more frequent and severe
- Nausea and Vomiting for no reason
- Changes in speech, vision, or hearing
- Problems balancing or walking
- Changes in mood, personality, or ability to concentrate
- Problems with memory
- Muscle jerking or twitching (seizures or convulsions)
- Numbness or tingling in the arms or legs
- Gradual loss of sensation or movement in an arm or a leg
- Confusion in everyday matters
- Personality or behavior changes
What are the common types of primary brain tumors?
There are many types of primary brain tumors. Among adults, the most common types are:
Gliomas. These tumors begin in the brain or spinal cord and include astrocytomas, ependymoma, glioblastomas, oligoastrocytomas, and oligodendrogliomas
Meningiomas. A meningioma is a tumor that arises from the meninges that surround the brain and spinal cord. Most meningiomas are noncancerous.
Acoustic neuromas (schwannomas). These are benign tumors that develop on the nerves that control balance and hearing leading from your inner ear to your brain.
Pituitary adenomas. These are mostly benign tumors that develop in the pituitary gland at the base of the brain. These tumors can lead to headaches, affect the vision, and cause an imbalance in pituitary hormones with effects throughout the body.
Among children, the most common types of brain tumors are:
- Medulloblastoma: The tumor usually arises in the cerebellum. It's sometimes called a primitive neuroectodermal tumor.
- 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 is most commonly found in children and young adults.
- Brain stem 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.
- Craniopharyngioma: The tumor arises from a developmental structure called the craniopharyngeal duct (or Rathke's pouch). While these tumors are sometimes referred to as benign (which means they are not cancerous and will not spread to other parts of the body), they are an issue because they have a tendency to become attached to or push on the critical brain structures that surround the area where they grow.
Secondary (metastatic) brain tumors are tumors that result from cancer that starts elsewhere in your body and then spreads (metastasizes) to the brain.
Secondary brain tumors most often occur in people who have a history of cancer. But in rare cases, a metastatic brain tumor may be the first sign of cancer that began elsewhere in our body.
Any cancer can spread to the brain, but the most common types include:
- Breast cancer
- Colon cancer
- Kidney cancer
- Lung cancer
- Melanoma
What are the causes and risk factors for brain tumors?
No one knows the exact causes of brain tumors, but studies do suggest that there may be many factors that play a role in their development. Risk factors for brain tumors include:
- Ionizing radiation: Ionizing radiation from high-dose X-rays (such as radiation therapy from a large machine aimed at the head) and other sources can cause cell damage that leads to a tumor.
- Family history: It is rare for brain tumors to run in a family. Only a very small number of families have several members with brain tumors.
What procedures and tests diagnose the type and grade of a brain tumor?
A neurological exam: clinical examination is the first thing to do and may include, among other things, checking vision, hearing, balance, coordination, strength, and reflexes.
- MRI: This is the most important modality used to make detailed pictures of areas inside your head. Sometimes a special dye (contrast material) is injected into a blood vessel in your arm or hand to help show differences in the tissues of the brain. The pictures can show abnormal areas, such as a tumors.
- CT scan: This is another useful imaging technology to make a diagnosis regarding brain tumors.
Sometimes, PET scans, which help doctors see the activity of the brain, may help diagnose primary brain cancer and are also very useful with metastatic disease.
Biopsy: A brain biopsy is a procedure to remove a sample of abnormal tissue for examination under a microscope. The tissue cells taken during the biopsy can show what kind of brain lesion (abscess, tumor) is present and whether it is benign (not cancerous) or cancerous (malignant).
- Biopsy at the same time as treatment: The surgeon takes a tissue sample when you have surgery to remove part or all of the tumor.
- Stereotactic biopsy: The patient is made to wear a rigid head frame for this procedure. The surgeon makes a small incision in the scalp and drills a small hole (a burr hole) into the skull. CT or MRI is used to guide the needle through the burr hole to the location of the tumor. The surgeon withdraws a sample of tissue with the needle. A needle biopsy may be used when a tumor is deep inside the brain or in a part of the brain that can't be operated on.
Leksell frame for stereotactic biopsy
What are the treatments for benign and cancerous brain tumors?
Surgery –Surgery is the usual first treatment for most brain tumors. Surgery to open the skull is called a craniotomy. A navigation system helps to make a craniotomy in less time, less blood loss, smaller incision and with precision and prevents damage to the normal brain.
With high-definition microscopes, brain tumors are removed. Sometimes, complete removal of tumors is not possible. Only debulking of tumors is done in such cases.
Radiation therapy - Radiation therapy kills brain tumor cells with high-energy x-rays, gamma rays, or protons. Radiation therapy usually follows surgery. The radiation kills tumor cells that may remain in the area. Sometimes, people who can't have surgery have radiation therapy instead.
Radiosurgery -Stereotactic radiosurgery is not a form of surgery in the traditional sense. Instead, radiosurgery uses multiple beams of radiation to give a highly focused form of radiation treatment to kill the tumor cells in a very small area. Radiosurgery is usually the preferable treatment for benign tumors with smaller sizes.
There are different types of technology used in radiosurgery to deliver radiation to treat brain tumors, such as a Gamma Knife or Cyberknife.
Radiosurgery is typically done in one treatment, and in most cases, you can go home the same day.
Chemotherapy –Chemotherapy is the use of drugs to kill cancer cells. It is sometimes used to treat brain tumors. Drugs may either be given by mouth or intravenous route. For some adults with high-grade glioma, the surgeon implants
several chemotherapy drugs containing wafers into the brain.
Each wafer is about the size of a dime. Over several weeks, the wafers dissolve, releasing the drug into the brain.
Targeted therapy - Targeted therapy drugs are a newer category of treatment that directly attacks changes in cancer cells. Avastin is one of these drugs.
Follow-up: Regular checkups after treatment for a brain tumor are needed. Checkups help ensure that any changes in your health are noted and treated if needed. Checkups may include careful physical and neurologic exams, as well as MRI or CT scans.
Rehabilitation in the form of speech, physical, and occupational therapies is also very important for a good recovery.
Category:Brain Tumor
