Kelley Mack, a promising actress known for her roles in popular television series, passed away at the age of 33 in August 2025 after a courageous fight against a rare form of brain cancer. Her performance in The Walking Dead had garnered significant acclaim, and she was actively promoting her upcoming projects even during her illness.
Who Was Kelley Mack?
Born in Ohio, Mack was not only an actress but also a producer and voiceover artist. According to her IMDb profile, she gained recognition for her roles in productions such as Broadcast Signal Intrusion, season 8 of Chicago Med, and season 9 of The Walking Dead.
In The Walking Dead, she portrayed the character Addy, contributing to the show’s dynamic narrative during its ninth season. As her career began to flourish, she faced an unexpected and severe health challenge.
Kelley Mack’s Health Journey
In January 2025, Mack shared with her fans that she had been diagnosed with a rare type of astrocytoma known as diffuse midline glioma. This diagnosis came after experiencing persistent lower back pain, which led her to seek medical attention. An Instagram post from Mack detailed her symptoms, including neuropathic itching and shooting pains that significantly affected her mobility.
Following a series of emergency MRIs, doctors discovered an abnormal mass in her spinal cord. Mack underwent a biopsy, which resulted in the loss of mobility in her right leg and most of her left leg. Despite these challenges, she maintained a positive outlook and expressed determination to continue her acting career, noting that it would be “somewhat paused for a little” during her treatment.
Mack’s resilience shone through as she reassured her followers that she had projects “coming out soon” and emphasized that her cancer battle would be “a short chapter in [her] long book.”
In her final months, she remained committed to her craft, even while undergoing treatment at a facility in Cincinnati, Ohio.
Understanding Diffuse Midline Glioma
A glioma is a malignant tumor that originates from glial cells, which are essential for the function of the central nervous system. According to the National Cancer Institute, these tumors can vary in type, including astrocytomas, ependymomas, and oligodendrogliomas. Mack’s diagnosis, diffuse midline glioma, is classified under astrocytomas, which can also encompass more aggressive forms such as glioblastomas and diffuse intrinsic pontine gliomas (DIPGs).
The prognosis for diffuse midline gliomas often remains challenging, and treatment options can be limited.
Although the specific cause of Kelley Mack’s death has not been disclosed, her bravery and positive spirit throughout her illness left a lasting impact on her fans and colleagues in the entertainment industry. Mack’s journey highlights the importance of awareness and understanding of rare cancers, as well as the resilience that individuals can display in the face of adversity.