Kelley Mack’s death at 33 is putting glioma under the spotlight.
After news broke that The Walking Dead and 9-1-1 star had died on Saturday, August 2, fans were reminded that the actress was recently diagnosed with glioma of the central nervous system.
“In September, I moved into a new apartment with my boyfriend, Logan. For a month after that, I had persistent lower back pain and thought I slipped a disc,” Mack shared via Instagram in January. “A few weeks later, I had neuropathic itching in my right quad. And then, the shooting pains in my legs and back began, which resulted in me having to sleep in a recliner for a month because laying down was too painful. On Thanksgiving Eve, I had emergency MRIs done at the hospital, which revealed an abnormal mass in my spinal cord.”
Mack said she was later diagnosed with diffuse midline glioma or an extremely rare type of astrocytoma cancer.
As family and friends continue to mourn the death of Mack, Us Weekly is taking a deeper look at the actress’ health battle.
Keep reading to learn more about glioma and what Mack may have experienced during her fight:
What Is Glioma?
Kelley Mack Courtesy of Kelley Mack / Instagram
According to the Mayo Clinic, glioma is a growth of cells that starts in the brain or spinal cord. As a glioma grows, it forms a mass of cells called a tumor.
The tumor can grow to press on the brain or spinal cord tissue and cause symptoms. Symptoms depend on which part of the brain or spinal cord is affected.
Common signs and symptoms of gliomas include headache, memory loss, vision problems, speech difficulties and even seizures.
How Many People Are Diagnosed With Glioma?
About 80,000 people are newly diagnosed with primary brain tumors each year in the United States, according to the Cleveland Clinic. Approximately 25 percent of these are gliomas.
How Is Glioma Treated?
Kelley Mack Courtesy of Kelley Mack / Instagram
Many patients are diagnosed with glioma after an MRI is conducted to capture pictures of the brain. A neurological exam is also usually performed to test a patient’s nerves and brain function.
Glioma treatment usually begins with surgery, the Mayo Clinic stated. Surgery, however, isn’t always an option.
If the glioma grows into important parts of the brain, it might be too risky for doctors to remove all of the glioma. Radiation therapy and chemotherapy may be recommended as an alternative for treatment.
What Is the Outlook for Patients With Glioma?
Kelley Mack Courtesy of Kelley Mack / Instagram
According to the Cleveland Clinic, survival rates for gliomas vary by tumor type, tumor grade and a person’s age.
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The older someone is when they’re diagnosed and treated, the worse the outlook.
Months before her death in August 2025, Kelley Mack praised her boyfriend, Logan Lanier, for his endless support throughout her battle with a rare form of cancer. Mack announced via Instagram in January 2025 that she had been diagnosed with diffuse midline glioma (DMG), an “extremely rare type of astrocytoma cancer.” At the same time, […]
Why Did Kelley Mack Share Her Diagnosis?
In recent months, Mack documented doctors’ appointments, physical therapy sessions and more milestones in her health journey.
“I just wanted to share this to be open about what I’m going through, in case any of you can relate or have been given a similar diagnosis,” she wrote via Instagram in January. “I am so thankful for the support everyone has given me throughout my acting career I love so much, which will also be somewhat paused for a little while as I undergo radiation treatment in Cincinnati, where my family is located. I do have some projects coming out soon, which I will of course share once they are released.”
