Background: Emergency medicine is instrumental in addressing undifferentiated patient concerns, particularly those related to non-traumatic back pain. While a significant portion of these presentations are benign, it is essential to maintain a systematic approach to identifying individuals with serious underlying conditions. Case Presentation: A 47-year-old man presented with six months of escalating upper back pain. He had been slated for a magnetic resonance imaging (MRI) scan through an outpatient neurosurgery clinic, but this was delayed. A thoracic spine computed tomography scan in the emergency department revealed notable abnormalities at the T9 vertebral level. A subsequent MRI detected a major bone lesion with tumor intrusion into the spinal canal. Diagnosis revealed metastatic thyroid papillary carcinoma, leading to surgical interventions and subsequent treatments. Conclusion: Given the frequency with which back pain concerns are addressed across medical specialties, it is vital to recognize potential red flags and adhere to a structured assessment approach. Timely imaging, guided by the patient's presentation and physical examinations, reduces the risk of missing serious pathologies.

Keywords: Back pain, red flags, MRI, CT scan, structured approach.