By: Kathy Hubbard
Astrocytes are star-shaped cells that help keep nerve cells healthy and working just like they’re supposed to. They are glial cells which provide supportive tissue in your brain. Astrocytoma is the most common glioma. It occurs when a tumor forms because glial cells grow out of control. Astrocytomas can be benign or malignant.
Mayo Clinic tells us that “symptoms depend on where the tumor is in the brain or spinal cord. These brain tumor symptoms can change as the tumor grows. Early symptoms come from local irritation of the nearby brain tissue. Later symptoms happen as the brain tumor grows and pressure builds in the brain or spinal cord.”
Early symptoms include seizures; subtle changes in thinking, mood or memory; mild headaches; difficulty finding the right words to say; changes in vision; clumsiness on one side of the body; pain in the neck or back that begins slowly; tingling or numbness that travels into an arm or leg, and fatigue. If you experience these symptoms see your primary care provider right away.
“Astrocytomas are sorted into grades depending on how their cells appear and act under a microscope. The World Health Organization created this grading system to help predict how quickly the tumor might grow or spread and to guide treatment decisions.”
Grade 1 is called pilocytic astrocytoma, and it is the least aggressive and considered benign. It grows slowly and when seen in a scan has clear edges. Surgery is often successful and people are cured. It accounts for two percent of all brain tumors and most often affects children and teens.
Grade 2, diffuse astrocytoma, is slow growing but “often grows into nearby brain tissue, which can make complete removal difficult,” Mayo says. “Cells look only slightly different from typical under the microscope. Treatment usually involves surgery to remove as much of the tumor is safely possible followed by radiation or chemotherapy or both.”
Diffuse astrocytoma mostly happens to those aged twenty to sixty, and accounts for between two and five percent of all brain tumors.
Four percent of all brain tumors are Grade 3. Identified as anaplastic astrocytoma they affect adults between thirty and sixty. It grows faster than Grade 2 and is more serious. “Anaplastic astrocytoma requires more aggressive treatment. Treatment usually involves surgery to remove as much tumor as safely possible, followed by radiation therapy and chemotherapy. Overall median survival is about five years or longer depending on the tumor type.”
And lastly, 24 percent of tumors are Grade 4, glioblastoma. It is the most aggressive. “Glioblastoma can arise from a lower grade tumor or appear suddenly as high-grade disease. Most common in older adults, treatment is usually surgery followed by radiation and chemotherapy,” Mayo says.
Cleveland Clinic says that “researchers don’t know the exact cause of most astrocytomas. The majority of these tumors are sporadic, meaning that they happen randomly. So far, researchers have only identified two known risk factors for astrocytomas: radiation exposure and genetics.
“However, recent studies have revealed that a mutation in the IDH1 gene contributes significantly to the development of low-grade astrocytomas. This gene helps provide energy to your cells. Its mutation results in the production of a chemical called 2-HG, which, over time, builds up inside healthy astrocytes. This buildup causes the cells to become abnormal causing astrocytomas.”
I won’t get into describing all of them, but there are rare genetic conditions that are associated with the development of astrocytomas. Your healthcare provider will explain it all to you, or you can read about them on Cleveland Clinic’s website.
Astrocytomas can be difficult to diagnose because the symptoms are similar to other neurological conditions. After discussing your medical history, your provider may order a brain imaging test.
“Magnetic resonance imaging (MRI) is the best imaging test for finding and diagnosing astrocytoma. If you’re unable to have an MRI scan due to having a pacemaker or joint implant, a computed tomography (CT scan) is the next best option. If something abnormal appears on the brain imaging test, your provider will most likely recommend a biopsy or resection (tumor removal) to determine the diagnosis,” Cleveland Clinic explains.
The first step, of course, is to see your primary care provider. If you don’t have one, Bonner General Family Practice is accepting new patients. Call 208-265-2221 for an appointment.
Kathy Hubbard was a charter member of Bonner General Health Foundation. She can be reached at [email protected]. This article was written for publication in the Bonner County Daily Bee on September 23, 2026.