A 23-year-old woman initiated a running program and after 2 months began experiencing right hip joint pain and sharp pain at the iliac crest. Following evaluation by her primary care physician, she was referred to a physical therapist. Eighteen months later, the patient had developed a bony prominence at the iliac crest that was painful to touch. She returned to see her primary care physician. Radiographs of the right hip and pelvis were completed and showed a lytic lesion that warranted additional imaging. Computed tomography and magnetic resonance imaging precontrast and postcontrast were performed, and the patient was referred to an orthopaedic oncologist. Conclusive laboratory testing determined that the tumor was a chondromyxoid fibroma J Orthop Sports Phys Ther 2018;48(2):122. doi:10.2519/jospt.2018.7551.