Kelley Mack, a rising star in the entertainment industry, passed away at the age of 33 in August 2025 after a courageous fight against a rare form of brain cancer known as diffuse midline glioma. Her performances in popular series such as The Walking Dead and Chicago Med had garnered significant acclaim, and she was actively promoting upcoming projects even during her illness.
Career Highlights and Diagnosis
Born in Ohio, Mack was not only an actress but also a producer and voiceover artist. She gained recognition for her roles in various television shows, with her portrayal of Addy in season 9 of The Walking Dead being particularly noteworthy. Mack’s career was on the upswing, and she had plans to continue her work in film and television despite her health challenges.
In January 2025, Mack announced her diagnosis of a rare astrocytoma, specifically diffuse midline glioma, a type of brain tumor that affects the central nervous system. According to the National Cancer Institute, this tumor can originate in either the brain or spinal cord. Mack shared her symptoms on social media, starting with persistent lower back pain, which she initially attributed to a slipped disc. Eventually, she experienced debilitating pain and loss of mobility that required her to use a walker and wheelchair.
In her own words, Mack described the moment she learned of her condition: “On Thanksgiving Eve, I had emergency MRIs done at the hospital, which revealed an abnormal mass in my spinal cord.” Following a biopsy, she faced significant physical challenges but remained optimistic about her future.
Understanding Central Nervous System Gliomas
A glioma is a malignant tumor that arises from glial cells, which support the central nervous system. According to the Cleveland Clinic, there are three main types of gliomas: astrocytomas, ependymomas, and oligodendrogliomas. Within the category of astrocytomas, conditions like glioblastomas and diffuse intrinsic pontine gliomas (DIPGs) are included. Mack’s diagnosis of diffuse midline glioma placed her in a challenging medical situation, as this type of tumor is known for its aggressive nature and difficulty in treatment.
Despite her illness, Mack’s resilience shone through. She communicated with fans about her experience, emphasizing that her acting career would be “somewhat paused for a little” during her treatment but expressing her determination to return to the screen. “I know that this [cancer battle] will eventually be a short chapter in [my] long book,” she stated, showcasing her unwavering spirit.
Kelley Mack’s passing marks a significant loss for the entertainment community and her fans worldwide. The exact cause of her death has not been disclosed, but her story serves as a poignant reminder of the struggles faced by those battling cancer. Her legacy will undoubtedly continue to inspire many as they remember her talent and tenacity.
