A 36-year-old woman presents to the emergency department with persistent epigastric pain for 9 hours and vomiting twice after alcohol consumption. Past medical history is unremarkable. Physical exam: temperature 37.8°C, left upper quadrant tenderness with mild guarding. If after 2 weeks the patient develops fever (40°C), elevated WBC count (21×10<sup>9</sup>/L), and persistently high serum amylase, which complication of pancreatitis should be suspected?