BACKGROUND Pancoast tumors, also called superior sulcus tumors, are a rare type of cancer affecting the lung apex. These tumors can spread to the brachial plexus and spine and present with symptoms that appear to be of musculoskeletal origin. CASE REPORT A 59-year-old Asian man presented to a chiropractor in Hong Kong with a 1-month history of neck and shoulder pain and numbness that had been treated unsuccessfully with exercise, medications, and acupuncture. He had an active history of tuberculosis, which was currently treated with antibiotics, and a 50-pack-year history of smoking. Cervical magnetic resonance imaging (MRI) was performed urgently, revealing a small cervical disc herniation thought to correspond with radicular symptoms. However, as the patient did not respond to a brief trial of care, a thoracic MRI was urgently ordered, revealing a large superior sulcus tumor invading the upper to mid-thoracic spine. The patient was referred for medical care and received radiotherapy and chemotherapy with a positive outcome. A literature review identified 6 previously published cases in which a patient presented to a chiropractor with an undiagnosed Pancoast tumor. All patients had shoulder, spine, and/or upper extremity pain. CONCLUSIONS Patients with a previously undiagnosed Pancoast tumor can present to chiropractors given that these tumors may invade the brachial plexus and spine, causing shoulder, spine, and/or upper extremity pain. Chiropractors should be aware of the clinical features and risk factors of Pancoast tumors to readily identify them and refer such patients for medical care.