What are the different types of brain tumors?
The different types of brain tumors include the following:
- Gliomas – the most common type of brain tumor is a glioma. Gliomas begin from glial cells, which are the supportive tissue of the brain. There are several types of gliomas, categorized by where they are found and the type of cells that originated the tumor. The following are the different types of gliomas:
- Astrocytomas – glial cell tumors that are derived from connective tissue cells called astrocytes. These cells can be found anywhere in the brain or spinal cord. Astrocytomas are the most common type of childhood brain tumor. Astrocytomas are generally subdivided into high-grade or low-grade tumors. High-grade astrocytomas are the most malignant of all brain tumors. Astrocytomas are further classified for presenting signs, symptoms, treatment and prognosis, based on the location of the tumor. The most common location of these tumors is in the cerebellum, where they are called cerebellar astrocytomas. These persons usually have symptoms of increased intracranial pressure, headache and vomiting. There also can be problems with walking and coordination, as well as double vision.
- Brain stem gliomas – tumors found in the brain stem. Most brain stem tumors cannot be surgically removed because of the remote location and delicate and complex function this area controls. Brain stem gliomas occur almost exclusively in children; the group most often affected is the school-aged child. The child usually does not have increased intracranial pressure, but may have problems with double vision, movement of the face or one side of the body, or difficulty with walking and coordination.
- Ependymomas – also glial cell tumors. They usually develop in the lining of the ventricles or in the spinal cord. The most common place they are found in children is near the cerebellum. The tumor often blocks the flow of the cerebral spinal fluid, which bathes the brain and spinal cord), causing increased intracranial pressure. This type of tumor mostly occurs in children younger than 10 years of age. Ependymomas can be slow growing, compared to other brain tumors, but may recur after treatment is completed. Recurrence of ependymomas results in a more invasive tumor with more resistance to treatment.
- Optic nerve gliomas – found in or around the nerves that send messages from the eyes to the brain. They are frequently found in persons who have neurofibromatosis, a condition a child is born with that makes him or her more likely to develop tumors in the brain. Children with this type of tumor usually experience loss of vision, as well as hormone problems, since these tumors are usually located at the base of the brain, where hormonal control is located. These are typically difficult to treat due to the surrounding sensitive brain structures.
- Primitive neuroectodermal tumors (PNET) – can occur anywhere in the brain of a child, although the most common place is in the back of the brain near the cerebellum. When they occur here, they are called medulloblastomas. The symptoms depend on their location in the brain, but typically the child experiences increased intracranial pressure. These tumors are fast growing and often malignant, with occasional spreading throughout the brain or spinal cord.
- Medulloblastomas – one type of PNET that are found near the midline of the cerebellum. This tumor is rapidly growing and often blocks drainage of the cerebral spinal fluid, which bathes the brain and spinal cord), causing symptoms associated with increased intracranial pressure. Medulloblastoma cells can spread (metastasize) to other areas of the central nervous system, especially around the spinal cord. A combination of surgery, radiation and chemotherapy is usually needed to control these tumors.
- Craniopharyngioma – benign tumors that occur at the base of the brain near the nerves from the eyes to the brain, and the hormone centers. Most people with this type of brain tumor develop symptoms before the age of 20. Symptoms include headaches, as well as problems with vision. Hormonal imbalances are common, including poor growth and short stature. Symptoms of increased intracranial pressure also may be seen. Although these tumors are benign, they are hard to remove due to the sensitive brain structures that surround them.
- Pineal region tumors – many different tumors can arise near the pineal gland, a gland which helps control sleep and wake cycles. Gliomas are common in this region, as are pineal blastomas (PNET). In addition, germ cell tumors, another form of malignant tumor, can be found in this area. Tumors in this region are more common in children than adults, and make up 3 percent to 8 percent of pediatric brain tumors. Benign pineal gland cysts also are seen in this location, which makes the diagnosis difficult between what is malignant and what is benign. Biopsy or removal of the tumor is frequently necessary to tell the different types of tumors apart. Children with tumors in this region frequently experience headaches or symptoms of increased intracranial pressure. Treatment depends on the tumor type and size.