A Case Report of Acute Lymphoblastic Leukemia Presenting as Bilateral Knee Pain in a Healthy Runner

INTRODUCTION: Acute lymphoblastic leukemia (ALL) is typically a childhood disease but may present in older patients in rare occurrences. Due to its significant morbidity and mortality, early diagnosis is crucial. The symptoms of ALL may be non-specific, making the initial diagnosis difficult leading to delayed treatment. CASE REPORT: We present the case of a 34-year-old, healthy male runner presenting to the emergency department with a common complaint of bilateral knee pain, who was ultimately diagnosed with ALL with signs of tumor lysis syndrome leading to premature death. CONCLUSION: We discuss the presenting symptoms of acute lymphoblastic leukemia, which may include joint or knee pain as well as leukemic arthritis. We further discuss the importance of clinicians maintaining a high level of suspicion for the "bounce-back" patient and avoiding taking cognitive shortcuts.