Q. A 55-year-old male presents to the clinic with a two-month history of an itchy rash on his legs and abdominal pain. He reports that the rash has spread to other areas of his body, and that he has been experiencing swelling in his legs. He has lost 20 pounds over the past two months and has been feeling depressed. He also reports occasional diarrhea. On physical examination, his blood glucose level is elevated, and a blood test confirms he has hyperglycemia. A CT scan of his abdomen shows a mass in the pancreas. What is the most likely diagnosis for this patient?