Astrocytomas are tumors that develop from astrocytes, star-shaped support cells in the brain and spinal cord. At Columbia University Irving Medical Center/NewYork-Presbyterian Hospital, we specialize in diagnosing and surgically treating astrocytomas of the brain and spinal cord.
Astrocytomas that develop in the brain are the subject of this page.
Astrocytomas are the most common tumors in the family of tumors called gliomas. Gliomas are tumors that originate from glial cells, which are the cells that support the neurons in the brain. These include astrocytes, oligodendrocytes, and microglia. There are several types of astrocytomas, and the World Health Organization assigns each type a grade on a scale of one to four. Lower grades (Grade I and II) are assigned to slow-growing tumors that are typically benign, whereas higher grades indicate a fast-growing tumor that is malignant. Malignant tumors tend to invade surrounding healthy tissue, causing further damage. Lower-grade tumors can progress to become higher grade.
Types of astrocytomas include the following:
- Grade I: Juvenile pilocytic astrocytomas, sometimes called simply pilocytic astrocytomas, occur mostly in children and young adults. Often slow-growing, these tumors may require treatment on the basis of their size. Astrocytomas that grow in the cerebellum are usually this type.
- Grade II: Diffuse astrocytomas grow slowly and may spread to nearby tissues.
- Grade III: Anaplastic astrocytomas grow quickly and can spread to nearby tissues. These tumors are aggressive and require rigorous treatment.
- Grade IV: Glioblastoma multiforme, also called glioblastomas, grow rapidly and spread to nearby tissues. They are the most aggressive type of astrocytoma and require rigorous treatment.
Astrocytomas can also be classified by location:
- Brainstem gliomas are astrocytomas that grow in the brainstem. Located toward the base of the skull and above the back of the neck, the brainstem coordinates functions essential for life, including breathing and heart rate. Brainstem gliomas can be any grade, but they are usually high grade. They occur mostly in children and young adults.
- Pineal astrocytic tumors grow in a part of the brain called the pineal gland. This gland is a pea-sized region that produces the hormone melatonin, which regulates the sleeping and waking cycle. Pineal astrocytic tumors can be any grade.
Some astrocytomas contain astrocytes and another type of glial cell, oligodendrocytes. These tumors are called mixed gliomas, or oligoastrocytomas.
A patient may experience a variety of symptoms, depending on size, location, and grade of astrocytoma. Symptoms may include:
- Changes in personality or behavior
- Cognitive impairment
- Visual disturbances such as vision loss or nystagmus
The astrocytoma may cause increased intracranial pressure, which can injure the brain. Symptoms may include headache (particularly in the morning or upon waking), nausea, vomiting, and drowsiness.
A physical examination and neurological examination may be performed to identify symptoms of an astrocytoma. Imaging tests are then required to diagnose astrocytomas.
The standard imaging test is magnetic resonance imaging (MRI), which uses a magnet, radio waves, and a computer to show tumors and other soft tissue in the brain. However, people with pacemakers or certain other implanted metallic devices cannot undergo MRI. A good alternative is a computed tomography (CT) scan, which uses X-rays and a computer to visualize the skull, blood vessels and other structures. Often, a contrast agent (either swallowed as a pill or injected as a dye) is used with MRI and CT scan to enhance the tumor and make it more visible.
Imaging tests can detect an astrocytoma but usually cannot identify the type or grade. To “grade” the tumor, a biopsy is performed and a tissue sample is obtained. The sample can be obtained either during surgery to remove the tumor or using a less invasive method: stereotactic biopsy. During stereotactic biopsy, open surgery is not performed. Instead, advanced technology is used to guide a needle to the tumor location and obtain a tissue sample. The sample is then viewed under a microscope to confirm the grade and type of astrocytoma. This additional information helps guide treatment decisions.
Currently, the exact cause of astrocytomas is not well understood.
Astrocytomas can occur in children or adults. Most astrocytomas in children are low grade, whereas in adults most are high grade. About 40% of brain tumors in children are astrocytomas, making this the most common type of brain tumor in children.
Men and women can develop astrocytomas.
People with the rare conditions neurofibromatosis type 1, Turcot syndrome, Li-Fraumeni syndrome, or tuberous sclerosis are at increased risk of developing astrocytomas. These conditions are inherited, but all other astrocytomas occur spontaneously.
Treatment depends on the location and grade of an astrocytoma and requires our neurosurgeons to use a customized approach for each patient. In general, lower-grade astrocytomas require less intense treatment and have better outcomes than higher-grade tumors.
The standard treatment is for a neurosurgeon to perform a craniotomy in order to remove the astrocytoma surgically. The neurosurgeon’s goal during surgery is to remove all of the tumor, but this is not always possible, particularly for higher-grade tumors that have spread to nearby tissue. In some cases, a catheter with a laser tip can be used to access and destroy the tumor without performing a craniotomy.
Radiation therapy and/or chemotherapy may be used next to destroy any remaining tumor. However, for younger children, radiation therapy is typically avoided because the radiation can interfere with brain development.
Some astrocytomas are located where they cannot be surgically removed safely. Instead, radiation therapy and/or chemotherapy are used without surgery to shrink and destroy the astrocytoma.