Abstract
Cervical radiculopathy, with an incidence of approximately 85 per 100,000 individuals annually, is characterized by pain originating from cervical nerve root disruption. Accurate diagnosis is challenging because of the absence of a universally accepted gold standard, necessitating reliance on patient history, clinical examination, and diagnostic tests. Brachial plexus metastasis is a rare but clinically significant condition that can mimic common musculoskeletal disorders, such as cervical radiculopathy. Its nonspecific presentation often results in delayed diagnosis, particularly in patients with cancer presenting with persistent upper-limb pain. This case report explored the underdiagnosis of supraclavicular brachial plexus metastasis, initially misinterpreted as cervical disc herniation in a 62-year-old man with a history of lung cancer. Despite undergoing cervical-Racz catheter neuroplasty and other treatments, the patient's persistent right arm pain prompted further investigations. Chest computed tomography and positron emission tomography computed tomography ultimately revealed metastatic squamous cell carcinoma extending to the brachial plexus. This case underscores the critical need for comprehensive diagnostic evaluations and the consideration of metastatic neoplasms in patients with a history of cancer. It also highlights the rarity and clinical significance of brachial plexus metastasis. It emphasizes the importance of an integrated approach to care, addressing both oncological and musculoskeletal issues to improve patient outcomes.