Review Question - QID 108585

A 55-year-old male presents to his primary care physician for routine care. He has a longstanding history of type 2 diabetes mellitus, hypertension, and hyperlipidemia for which he takes metformin, amlodipine, and atorvastatin. He is generally happy with his health, but does complain of mild discomfort in his chest after dinner each night as well as intermittent itching of his upper back. He smokes one pack of cigarettes per day and drinks 2 glasses of wine on the weekends. He works as a landscaper at his local golf course. His temperature is 99.5°F (37.5°C), pulse is 70/min, blood pressure is 140/90 mmHg, and respirations are 12/min. The most recent hemoglobin A1c from two years prior was 6.4% and his fasting fingerstick glucose in the office today is 120 mg/dL. Physical exam is notable for a well-appearing overweight individual with the finding shown in Figure A on his upper back. Which of the following is the most likely diagnosis?