A rare complication of the duodenal diverticulum

Introduction An 80-year-old woman presented to the emergency department with severe right-sided abdominal pain that had started after her last meal. Physical examination revealed fever (38.6°C) and rebound tenderness in the right upper quadrant of the abdomen. The laboratory studies showed a leucocyte count of 11.3×10 9 /L (normal, 3.7–8.0×10 9 /L) and a C-reactive protein level of 2.34 mg/dL (normal, Question What is the most likely diagnosis and the cause underlying the condition?