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Brain tumor - children
 
Definition:

A tumor is any growth of abnormal cells, or the uncontrolled growth of cells. This article is about primary brain tumors. These start in the brain, rather than spreading to the brain from another part of the body.
Alternative Names:
Glioblastoma multiforme - children; Ependymoma - children; Glioma - children; Astrocytoma - children; Medulloblastoma - children; Neuroglioma - children; Oligodendroglioma - children; Meningioma - children; Cancer - brain tumor (children)
Causes, incidence, and risk factors:

Primary brain tumors include any tumor that starts in the brain. Tumors may be confined to a small area, invasive (spread to nearby areas), benign (not cancerous), or malignant (cancerous).

Tumors can directly destroy brain cells. They can also indirectly damage cells by producing inflammation, compressing other parts of the brain as the tumor grows, causing swelling in the brain, and increasing pressure within the skull.

Brain tumors are classified depending on the exact site of the tumor, the type of tissue involved, benign or malignant tendencies of the tumor, and other factors. The cause of primary brain tumors is unknown.

Tumors may occur at any age, but many specific tumors have a particular age group in which they are most common. The most common childhood brain tumors are gliomas, astrocytomas, medulloblastomas, ependymomas, and brain stem gliomas. Most brain tumors are rare in the first year of life.

Childhood nervous system tumors may be classified as either infratentorial (located below the tentorium cerebelli), meaning they are in the back third of the brain, or as supratentorial, meaning they are in the front two-thirds of the brain.

Central nervous system tumors, including brain tumors, account for about 20% of all childhood cancers. Only leukemias are more common.

The specific symptoms, treatment, and probable outcome vary according to the site and type of the tumor and the age and general health of the child.

SPECIFIC TUMOR TYPES

Cerebellar astrocytoma:

Accounts for about 20% of pediatric brain tumors (peak age is 5 to 8 years old).
Usually benign, cystic, and slow-growing.
Signs usually include clumsiness of one hand, stumbling to one side, headache, and vomiting.
The cornerstone of treatment is surgical removal of the tumor. If complete removal is not possible, radiation therapy may help. Chemotherapy is usually reserved for unremovable, progressive cases.
The cure rate varies, depending on the ability of the tumor to be completely removed by surgery, the tumor type, and the response to other therapies if needed.
Medulloblastoma:

The most common pediatric malignant brain tumor (10-20% of all pediatric brain tumors).
Occurs more frequently in boys than in girls. Peak age is about 5 years old. Most occur before 10 years of age.
Signs include headache, vomiting, uncoordinated movements, and lethargy.
Can spread (metastasize) along the spinal cord.
Surgical removal alone does not cure medullablastoma. Radiation therapy or chemotherapy are often used with surgery.
If the cancer returns, it is usually within the first 5 years of therapy.
Ependymoma:
Accounts for 8% to 10% of pediatric brain tumors.
Tumor growth rates vary.
Tumors are located in the ventricles of the brain and obstruct the flow of cerebrospinal fluid (CSF).
Signs include headache, vomiting, and uncoordinated movements.
Single or combination therapy includes surgery, radiation therapy, and chemotherapy.
The cure rate varies, depending on the ability of the tumor to be completely removed by surgery, the tumor type, and the response to other therapies if needed.
Brainstem glioma:
Tumor of the pons and medulla
Occurs almost exclusively in children
Accounts for 10% to 15% of primary brain tumors in children; average age is about 6 years old
May grow to very large size before symptoms are present
Signs include double vision, facial weakness, difficulty walking, vomiting.
Surgical removal is usually not possible due to the location of the tumor.
Radiation therapy and chemotherapy are used to shrink the tumor size and prolong life.
Overall 5-year survival rate is low.
Craniopharyngioma:
Tumor located near the pituitary stalk.
Often close to vital structure, making surgical removal difficult.
Rare, less than 10% of childhood brain tumors; average age is about 7 to 12 years old.
Signs include vision changes, headache, weight gain, endocrine changes.
Treated with surgery, radiation therapy, or a combination. There is some controversy over the optimal approach to therapy for craniopharyngioma.
Survival and cure rates are favorable, though endocrine dysfunction may persist as well as the effects of radiation on cognition (thinking ability).