A 65-year-old man presented to the clinic with complaints of difficulty swallowing. He notes that about 3 months ago he had trouble swallowing big pieces of food. This has progressed to the point that he has difficulty swallowing thick liquids now. He denies heartburn or other symptoms. He has lost 5 kg and attributes this to a lack of desire to eat. He has smoked 2 packs of cigarettes per day for 40 years. He is alert and oriented to person, place, and time. He is pale in appearance. Otherwise his examination is normal.