Kelley Mack tragically passed away at the young age of 33 in August 2025 after a courageous battle with a rare and aggressive form of brain cancer. At the time of her passing, she was experiencing a significant upswing in her acting career, particularly highlighted by her acclaimed role in The Walking Dead, which garnered a dedicated fan following. Mack was not only an actress but also a multi-talented individual who engaged in various creative projects and actively promoted her upcoming film endeavors in the final months of her life, showcasing her unwavering passion for her craft.

In this article, Hollywood Life provides a detailed explanation of the specific type of cancer that Kelley Mack faced, as well as a comprehensive overview of what a glioma entails, shedding light on this serious health issue.

Discover the Life and Career of Kelley Mack

Kelley Mack was a talented actress, producer, and voiceover artist whose work left a mark on the entertainment industry. According to her IMDb profile, she hailed from Ohio and gained recognition for her standout performances in Broadcast Signal Intrusion, season 8 of Chicago Med, and notably, season 9 of The Walking Dead. Her versatility and dedication to her craft made her a beloved figure among fans and colleagues alike, and her contributions to the industry will not be forgotten.

Who Did Kelley Mack Portray in the Iconic Series The Walking Dead?

In the critically acclaimed series The Walking Dead, Mack brought the character Addy to life during season 9. Her performance was not only memorable but also contributed to the show’s intricate narrative, showcasing her ability to engage audiences in a post-apocalyptic world filled with tension and drama.

What Type of Cancer Was Kelley Mack Diagnosed With?

In January 2025, Kelley Mack bravely disclosed her diagnosis of a rare and aggressive form of astrocytoma known as diffuse midline glioma. This type of brain tumor originates in the glial cells, which are essential for the normal functioning of the brain and spinal cord, according to the National Cancer Institute. The severity of this condition underscores the importance of awareness and research surrounding brain tumors and their impact on individuals and families.

Mack shared her personal experience on Instagram, revealing that after moving into a new apartment with her boyfriend, Logan, she began experiencing persistent lower back pain, which she initially thought was a slipped disc. This was followed by neuropathic itching in her right thigh and severe shooting pains in her legs and back, leading her to seek medical attention. On Thanksgiving Eve, emergency MRIs were conducted, revealing an abnormal mass in her spinal cord, marking a turning point in her health journey.

Following her biopsy surgery on the spinal cord, Mack faced significant physical challenges, including losing the use of her right leg and most of her left leg. This necessitated the use of a walker and wheelchair for mobility, demonstrating the rigorous physical toll the illness took on her body. Despite these challenges, her resilience shone through as she continued to advocate for her health and well-being.

Throughout this daunting journey, Mack maintained an inspiringly positive outlook on her cancer battle. She communicated her situation to fans, acknowledging that her acting career would undergo a temporary pause during her treatment in Cincinnati, Ohio. However, she remained optimistic, expressing excitement about upcoming projects and a strong belief that this chapter would eventually be a brief part of her longer, illustrious story in the world of entertainment.

What Is a Central Nervous System Glioma and Its Impact?

A glioma is classified as a malignant tumor that arises when glial cells, which play a crucial role in supporting the central nervous system, begin to grow uncontrollably. This type of tumor can have profound implications for brain function and overall health, as highlighted by resources from the Cleveland Clinic, which emphasize the need for increased awareness and research into these conditions.

Gliomas can be categorized into three primary types: astrocytomas, ependymomas, and oligodendrogliomas. Within the astrocytoma category, there are subtypes such as glioblastomas and diffuse intrinsic pontine gliomas (DIPGs), according to the Cleveland Clinic. Mack’s specific diagnosis of diffuse midline glioma is particularly concerning due to its aggressive nature and the challenges it poses in treatment and management.

How Did Kelley Mack’s Battle with Cancer End?

Kelley Mack sadly succumbed to her battle with cancer, leaving behind a legacy of strength and inspiration. While the exact cause of her death has not been publicly disclosed at the time of publication, her story continues to resonate with many and highlights the ongoing need for awareness and research surrounding brain cancer and its effects on individuals and families.