Shoulder and arm pain: A “red herring” chief complaint in a smoker diagnosed with Pancoast-Tobías syndrome

Abstract

Introduction: A Pancoast tumor is a rare apical lung cancer that can lead to a constellation of signs and symptoms known as Pancoast-Tobías syndrome, which involves ipsilateral shoulder and arm pain, Horner’s syndrome, and atrophy of the intrinsic hand muscles. As a Pancoast tumor progresses, it first invades the brachial plexus and causes unrelenting shoulder and arm pain in the C8-T2 nerve distributions. However, when evaluating this presenting symptom, it is often considered benign, especially in aging patients. Consequently, Pancoast-Tobías syndrome is easily misdiagnosed or delayed in diagnosis, resulting in poor prognosis, particularly for patients with advanced disease. Case Report: We present the case of an elderly Afro-Caribbean woman with a 24-pack-year smoking history who presented with unrelenting pain to the right shoulder and arm for two months. During that time, she visited multiple family physicians. Onset of pain coincided with a wasp sting that was complicated by a large local reaction. Despite clinical resolution of the inflammatory reaction, the pain persisted even with multi-modal oral analgesics. Detailed physical examination later revealed ipsilateral atrophy of the intrinsic hand muscles and focal chest findings concerning for an underlying consolidative lung process. This prompted diagnostic chest imaging, which identified a right-sided Pancoast tumor aggressively invading adjacent structures. She soon developed Horner’s syndrome, resulting in clinicoradiologic confirmation of Pancoast-Tobías syndrome. Conclusion: It is important to consider Pancoast-Tobías syndrome as an important differential of unrelenting shoulder and arm pain, even in the absence of pulmonary symptoms, in patients with risk factors for lung cancer, such as chronic smokers.