Astrocytoma
A tumor that begins in the brain's star-shaped support cells
Quick Facts
- Type: Primary brain or spinal cord tumor
- Cell of origin: Astrocytes (a type of glial cell)
- Grades: Low-grade to high-grade
- Common symptoms: Headache, seizures, focal weakness
Overview
An astrocytoma is a tumor that arises from astrocytes, the star-shaped cells that support and nourish nerve cells in the brain and spinal cord. Astrocytes belong to a larger family of cells called glia, so astrocytomas are a type of glioma. They are among the most common primary brain tumors, meaning tumors that start in the brain rather than spreading from elsewhere.
Astrocytomas vary greatly in behavior. They are graded from low to high based on how the cells look and how quickly they tend to grow. Low-grade astrocytomas grow slowly and may be present for years, while high-grade forms, including glioblastoma, grow rapidly. Treatment and outlook depend heavily on the grade, location, and other features of the tumor.
Symptoms
Symptoms depend on the tumor's size, grade, and location, since different parts of the brain control different functions. Common symptoms include:
- Headaches, which may be worse in the morning or with straining
- Seizures, often a first sign
- Weakness or numbness on one side of the body
- Changes in vision, speech, or balance
- Difficulty with memory, thinking, or personality changes
- Nausea or vomiting
Symptoms that come on suddenly or worsen quickly, such as a severe new headache, sudden weakness, or a first seizure, need prompt medical evaluation.
Causes
In most cases, the exact cause of an astrocytoma is not known. These tumors develop when astrocytes acquire genetic changes that cause them to grow abnormally. The reasons for these changes are usually unclear.
Known contributing factors are limited:
- Radiation exposure: Previous radiation therapy to the head increases risk.
- Inherited syndromes: Rare genetic conditions such as neurofibromatosis or Li-Fraumeni syndrome raise the risk.
Astrocytomas are not contagious, and for most people no preventable cause can be identified.
Risk Factors
- Previous radiation therapy to the brain
- Certain inherited genetic syndromes
- Increasing age for some high-grade types, though astrocytomas can occur at any age
- A family history of brain tumors in rare cases
Most people with an astrocytoma have no identifiable risk factor.
Diagnosis
Diagnosis usually involves imaging and tissue analysis:
- MRI: The main imaging test to detect the tumor, show its size and location, and plan treatment.
- CT scan: Sometimes used, especially in urgent situations.
- Biopsy or surgery: Removing a tissue sample to confirm the diagnosis, determine the grade, and test for genetic markers.
- Neurological exam: Testing strength, sensation, vision, balance, and reflexes.
Modern diagnosis also looks at specific molecular features of the tumor, which guide treatment and outlook.
Treatment
Treatment is individualized based on the tumor's grade, location, and molecular features, and on the person's overall health. It is managed by a specialist team.
- Surgery: Removing as much of the tumor as safely possible is often the first step.
- Radiation therapy: Used for higher-grade tumors or when surgery cannot remove all of the tumor.
- Chemotherapy: Medicines that target tumor cells, sometimes given with radiation.
- Targeted therapy and clinical trials: Newer treatments matched to the tumor's molecular profile may be options.
- Supportive care: Medicines to control seizures, reduce swelling, and manage symptoms.
For low-grade tumors, close monitoring may be appropriate. Care plans are tailored to each person.
When to See a Doctor
See a doctor if you have new or worsening headaches, especially with nausea, vision changes, or weakness. Seek emergency care right away for:
- A first-ever seizure
- Sudden severe headache, confusion, or loss of consciousness
- Sudden weakness, numbness, vision loss, or trouble speaking
These can be signs of a serious problem in the brain and need urgent assessment. Early evaluation allows for prompt diagnosis and treatment.
Frequently Asked Questions
What is an astrocytoma?
An astrocytoma is a tumor that begins in astrocytes, the star-shaped support cells of the brain and spinal cord. It is a type of glioma and is one of the more common tumors that start within the brain itself.
What do the grades of astrocytoma mean?
Astrocytomas are graded from low to high based on how the cells appear and how quickly they tend to grow. Low-grade tumors grow slowly, while high-grade tumors, including glioblastoma, grow quickly and are more aggressive. The grade strongly influences treatment and outlook.
What causes astrocytomas?
In most cases the cause is unknown. They develop when astrocytes acquire genetic changes that drive abnormal growth. Previous radiation to the head and certain rare inherited syndromes can increase risk, but most people have no identifiable cause.
How is an astrocytoma treated?
Treatment depends on the grade and location and may include surgery to remove the tumor, radiation therapy, and chemotherapy. Newer targeted treatments and clinical trials may also be options. Low-grade tumors are sometimes monitored closely rather than treated immediately.
What symptoms should prompt urgent care?
Seek emergency care for a first seizure, sudden severe headache, confusion, loss of consciousness, or sudden weakness, numbness, vision loss, or trouble speaking. These can signal a serious brain problem that needs immediate evaluation.
References
- National Cancer Institute (NCI). Adult Central Nervous System Tumors Treatment.
- American Brain Tumor Association. Astrocytoma.
- Mayo Clinic. Astrocytoma.
- MedlinePlus, U.S. National Library of Medicine. Brain tumor.