Types

There is no staging for childhood brain tumors. Brain tumors are grouped according to their location within the brain and the appearance and behavior of the tumor tissue. The following groupings are used for childhood brain tumors:

Infratentorial tumors

Infratentorial tumors are those that occur in the lower part of the brain. Tumors found in this region include:

Medulloblastoma

Childhood medulloblastoma (tumor) usually forms in the cerebellum, which is at the lower back of the brain. The cerebellum is the part of the brain that controls movement, balance, and posture. Childhood medulloblastoma may also be called primitive neuroectodermal tumor (PNET). About 1 out of 5 childhood brain tumors are medulloblastomas.

Cerebellar astrocytoma

Astrocytomas are tumors that develop from brain cells called astrocytes. Cerebellar astrocytomas start in the cerebellum, which is located at the lower back of the brain. The cerebellum is the part of the brain that controls movement, balance, and posture. About 15-25% of all childhood brain tumors are cerebellar astrocytomas.

Infratentorial ependymoma

Ependymal tumors are tumors that begin in the ependyma, the cells that line the hollow cavities within the brain (called ventricles) which are filled with cerebrospinal fluid). The growth of ependymal tumors can obstruct the flow of the cerebrospinal fluid through the brain and spinal cord. Infratentorial ependymomas begin in the lower part of the brain. These tumors may spread via the cerebrospinal fluid to other areas of the brain and spinal cord.

Brain stem glioma

The brain stem is the part of the brain connected to the spinal cord. It is located in the lowest part of the brain, just above the back of the neck. The brain stem is the part of the brain that controls breathing, heart rate, and nerves and muscles used in seeing, hearing, walking, talking, and eating. Most childhood brain stem gliomas are pontine gliomas, which form in a part of the brain stem called the pons.

Supratentorial tumors

Supratentorial tumors are those that occur in the upper part of the brain. Common supratentorial tumors include:

Cerebral astrocytoma

Astrocytomas are tumors that start in brain cells called astrocytes. Cerebral astrocytomas form in the area of the brain called the cerebrum. The cerebrum, which is at the top of the head, is the largest part of the brain. The cerebrum controls thinking, learning, problem-solving, speech, emotions, reading, writing, and voluntary movement.

Supratentorial ependymoma

Ependymal tumors are tumors that begin in the ependyma, the cells that line the hollow cavities within the brain (called ventricles) which are filled with cerebrospinal fluid. The growth of ependymal tumors can obstruct the flow of the cerebrospinal fluid through the brain. Supratentorial ependymomas begin in the upper part of the brain. These tumors may spread to other areas of the brain and spinal cord, depending on their grade.

Craniopharyngioma

Craniopharyngiomas are tumors that generally occur just above the pituitary gland. Located at the bottom of the brain, the pituitary gland is about the size of a pea and controls many vital functions. Craniopharyngiomas do not spread, but may interfere with important structures near them, causing serious problems.

Central nervous system germ cell tumor

Germ cell tumors arise from the sex cells found in the brain. There are different types of germ cell tumors, including germinomas, embryonal cell carcinomas, choriocarcinomas, and teratomas. These tumors usually occur in the center of the brain, and can spread to other parts of the brain and spinal cord.

Supratentorial primitive neuroectodermal tumors and pineoblastoma

Childhood supratentorial primitive neuroectodermal tumors start in the cerebrum. The cerebrum, which is at the top of the head, is the largest part of the brain. The cerebrum controls thinking, learning, problem solving, speech, emotions, reading, writing, and voluntary movement. Childhood supratentorial primitive neuroectodermal tumors are also called cerebral neuroblastomas or cerebral medulloblastomas.

Pineoblastoma form in or near the pineal gland. The pineal gland is a tiny organ in the brain that produces melatonin, a substance that helps control our sleeping and waking cycle.

Visual pathway and hypothalamic glioma

Gliomas are a type of astrocytoma, tumors that start in brain cells called astrocytes. A visual pathway glioma occurs along the nerve that sends messages from the eye to the brain (the optic nerve). Visual pathway gliomas are visual pathway tumors. They may grow rapidly or slowly, depending on the grade of the tumor.

The hypothalamic glioma is a tumor in the hypothalamus.

Reference:

National Cancer Institute, USA.