Relevant information about brain tumors. I've had several cases of patients having brain tumor, one of the most memorable(is this word politically correct?) was that of the tumor actually caused a rupture of a minor vessel which lead to internal hemorrhage. Read on for a detailed insight into Brain Neoplasms.
Neoplasms of the intracranial components of the central nervous system, including the cerebral hemispheres, basal ganglia, hypothalamus, thalamus, brain stem, and cerebellum. Brain neoplasms are subdivided into primary (originating from brain tissue) and secondary (i.e., metastatic) forms. Primary neoplasms are subdivided into benign and malignant forms. In general, brain tumors may also be classified by age of onset, histologic type, or presenting location in the brain.
Benign brain tumors do not contain cancer cells:
Usually, benign tumors can be removed, and they seldom grow back.
The border or edge of a benign brain tumor can be clearly seen. Cells from benign tumors do not invade tissues around them or spread to other parts of the body. However, benign tumors can press on sensitive areas of the brain and cause serious health problems.
Unlike benign tumors in most other parts of the body, benign brain tumors are sometimes life threatening.
Very rarely, a benign brain tumor may become malignant.
Malignant brain tumors contain cancer cells:
Malignant brain tumors are generally more serious and often are life threatening.
They are likely to grow rapidly and crowd or invade the surrounding healthy brain tissue.
Very rarely, cancer cells may break away from a malignant brain tumor and spread to other parts of the brain, to the spinal cord, or even to other parts of the body. The spread of cancer is called metastasis.
Sometimes, a malignant tumor does not extend into healthy tissue. The tumor may be contained within a layer of tissue. Or the bones of the skull or another structure in the head may confine it. This kind of tumor is called encapsulated.
- Doctors sometimes group brain tumors by grade—from low grade (grade I) to high grade (grade IV). The grade of a tumor refers to the way the cells look under a microscope. Cells from high-grade tumors look more abnormal and generally grow faster than cells from low-grade tumors.
Primary Brain Tumors
Tumors that begin in brain tissue are known as primary tumors of the brain. (Information about secondary brain tumors appears in the following section.) Primary brain tumors are named according to the type of cells or the part of the brain in which they begin.
The most common primary brain tumors are gliomas. They begin in glial cells. There are many types of gliomas:
Astrocytoma—The tumor arises from star-shaped glial cells called astrocytes. In adults, astrocytomas most often arise in the cerebrum. In children, they occur in the brain stem, the cerebrum, and the cerebellum. A grade III astrocytoma is sometimes called an anaplastic astrocytoma. A grade IV astrocytoma is usually called a glioblastoma multiforme.
Brain stem glioma—The tumor occurs in the lowest part of the brain. Brain stem gliomas most often are diagnosed in young children and middle-aged adults.
Ependymoma—The tumor arises from cells that line the ventricles or the central canal of the spinal cord. They are most commonly found in children and young adults.
Oligodendroglioma—This rare tumor arises from cells that make the fatty substance that covers and protects nerves. These tumors usually occur in the cerebrum. They grow slowly and usually do not spread into surrounding brain tissue. They are most common in middle-aged adults.
Some types of brain tumors do not begin in glial cells. The most common of these are:
Medulloblastoma—This tumor usually arises in the cerebellum. It is the most common brain tumor in children. It is sometimes called a primitive neuroectodermal tumor.
Meningioma—This tumor arises in the meninges. It usually grows slowly.
Schwannoma—A tumor that arises from a Schwann cell. These cells line the nerve that controls balance and hearing. This nerve is in the inner ear. The tumor is also called an acoustic neuroma. It occurs most often in adults.
Craniopharyngioma—The tumor grows at the base of the brain, near the pituitary gland. This type of tumor most often occurs in children.
Germ cell tumor of the brain—The tumor arises from a germ cell. Most germ cell tumors that arise in the brain occur in people younger than 30. The most common type of germ cell tumor of the brain is a germinoma.
Pineal region tumor—This rare brain tumor arises in or near the pineal gland. The pineal gland is located between the cerebrum and the cerebellum.
Secondary Brain Tumors
When cancer spreads from its original place to another part of the body, the new tumor has the same kind of abnormal cells and the same name as the primary tumor. Cancer that spreads to the brain from another part of the body is different from a primary brain tumor. When cancer cells spread to the brain from another organ (such as the lung or breast), doctors may call the tumor in the brain a secondary tumor or metastatic tumor. Secondary tumors in the brain are far more common than primary brain tumors.
Brain Tumors: Who's at Risk?
No one knows the exact causes of brain tumors. Doctors can seldom explain why one person develops a brain tumor and another does not. However, it is clear that brain tumors are not contagious. No one can "catch" the disease from another person.
Research has shown that people with certain risk factors are more likely than others to develop a brain tumor. A risk factor is anything that increases a person's chance of developing a disease.
The following risk factors are associated with an increased chance of developing a primary brain tumor:
Being male—In general, brain tumors are more common in males than females. However, meningiomas are more common in females.
Race—Brain tumors occur more often among white people than among people of other races.
Age—Most brain tumors are detected in people who are 70 years old or older. However, brain tumors are the second most common cancer in children. (Leukemia is the most common childhood cancer.) Brain tumors are more common in children younger than 8 years old than in older children.
Family history—People with family members who have gliomas may be more likely to develop this disease.
Being exposed to radiation or certain chemicals at work:
Radiation—Workers in the nuclear industry have an increased risk of developing a brain tumor.
Formaldehyde—Pathologists and embalmers who work with formaldehyde have an increased risk of developing brain cancer. Scientists have not found an increased risk of brain cancer among other types of workers exposed to formaldehyde.
Vinyl chloride—Workers who make plastics may be exposed to vinyl chloride. This chemical may increase the risk of brain tumors.
Acrylonitrile—People who make textiles and plastics may be exposed to acrylonitrile. This exposure may increase the risk of brain cancer.
Scientists are investigating whether cell phones may cause brain tumors. Studies thus far have not found an increased risk of brain tumors among people who use cell phones.
Scientists also continue to study whether head injuries are a risk factor for brain tumors. So far, these studies have not found an increased risk among people who have had head injuries.
Most people who have known risk factors do not get brain cancer. On the other hand, many who do get the disease have none of these risk factors. People who think they may be at risk should discuss this concern with their doctor. The doctor may be able to suggest ways to reduce the risk and can plan an appropriate schedule for checkups.
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