1. A 58-year-old man presents with abdominal pain and new onset diabetes. He undergoes a distal pancreatectomy for a 8 cm mass in the tail of the pancreas. The tumor is soft and fleshy. Microscopically, the tumor shows a solid pattern with cells lacking evident polarization. There are numerous mitotic figures, with some appearing atypical. The cells have abundant granular eosinophilic cytoplasm and a single, central, prominent nucleolus. What is the most likely diagnosis?