Lung cancer and mesothelioma Quiz: Ace Your Exams

A 60-year-old man comes to the physician’s office due to a 2-month history of pain and numbness in his right shoulder and arm. The patient describes the pain as dull and deep, and it often awakens him at night. He tried some over-the-counter pain medications with minimal relief. The patient's medical history is significant for hypertension, cholelithiasis, and gastroesophageal reflux disease. He smoked 1 pack of cigarettes per day since he was 25 years old but quit 2 years ago. On physical examination, 3/5 strength is noted on the right upper extremity, and hypoesthesia is present along the distribution of C8-T1 dermatomes. Eye examination reveals left side ptosis and miosis. Which of the following is most likely responsible for this patient’s presentation?